# 3 TB on eSata



## echo (Aug 18, 2007)

After reading the long thread on the eSata port being activated, I decided to hook up an eSata array to my HR20. I got an enclosure and put in three Hitachi 1 TB drives (3 TB total) and set them up in a RAID-0 array.

It's working fine, but the free space reported seems to be wrong. Just wondering if anyone out there can help me with the math and let me know if this seems right???

Here are the total hours I have recorded (actually recorded, not just scheduled to record):
- 1 hr in HD through DTV
- 1/2 hr in HD through over the air antenna (digital local)
- 5 1/2 hrs in non-HD through over the air antenna (digital local)
- 5 hrs in non-HD through DTV

My system is currently reporting 91% free space. I don't know all the ratios, but I'm thinking with 3 terrabytes of space, that amount of recorded shows should NOT be taking up 9% of my space. Doesn't that seem wrong?

I tested the eSata array to make sure it was being used (and not the internal drive instead) and I'm fairly certain it is working ok. To test it, I took out one of the Hitachi drives while I was watching a recorded show and it immediately froze. Once I put the drive back in and restarted everything it worked fine again.

Also, I'm fairly certain the system is using the eSata array because I had shows already recorded on the internal drive and once I hooked up the eSata array it did all the software downloading steps and once it booted up, my recorded shows were gone.

So, any advice? Do you think those shows listed above really take up 9% of a 3 TB array? Or is the free space just being reported incorrectly? 

Maybe the HR20 isn't able to correctly estimate free space when there is 3 TB? If that is the case, do you think it will use the full 3 TB and just report incorrectly, or will I not be able to take advantage of that much space?

Any thoughts are appreciated. I've read a lot of posts on this board and I'm hoping some of the gurus here might be able to point me in the right direction.

Thanks.


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## Michael D'Angelo (Oct 21, 2006)

To me it seems like only 1 hard drive is working right and it is only seeing 1TB. 

I know it will work with 3TB. Someone posted a couple of months ago about he is using 3.5TB with no problems at all.


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## echo (Aug 18, 2007)

I took out 2 of 3 drives (on different occassions) while watching a recorded show, and both times the system froze. That made me think all the drives were working. Do you think maybe it's a problem with the RAID setup? It's weird cause it's clearly working ok, just not reporting the right amount of space. How do you fix something that's working ok but not really working ok?


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## Michael D'Angelo (Oct 21, 2006)

echo said:


> I took out 2 of 3 drives (on different occassions) while watching a recorded show, and both times the system froze. That made me think all the drives were working. Do you think maybe it's a problem with the RAID setup? It's weird cause it's clearly working ok, just not reporting the right amount of space. How do you fix something that's working ok but not really working ok?


Did you install all of the drives before you connected it to the HR20 or did you try to add the other two after the first one was already connected and working?


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## echo (Aug 18, 2007)

I installed them all together and setup the RAID array all together.


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## Michael D'Angelo (Oct 21, 2006)

echo said:


> I installed them all together and setup the RAID array all together.


Then I am not sure. Something does not seem like it is working right. Hopefully someone that knows more about this can help.


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## Stuart Sweet (Jun 19, 2006)

What are you using to set up the RAID? Does it have any diagnostics?


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## echo (Aug 18, 2007)

I emailed tech support for the company that made the enclosure, waiting to hear back from them. 

I just find it weird that it seems to be working and recording shows, but not displaying the right free space.


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## echo (Aug 18, 2007)

I guess there is software included in the enclosure to setup the RAID cause it did so automatically when I first turned it on. It has diagnostics and I've paged through them, and its showing everything perfectly. It sees three separate drives of 1000 GB each and reports a total size of 3000 GB. 

Maybe the tech support over there will have some more insight. Kind of frustrating to only get the use of 1 TB when you pay for 3 TB....


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## Nick (Apr 23, 2002)

Welcome to DBSTalk...echo...welcome to DBSTalk. :hi:


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## PoitNarf (Aug 19, 2006)

If it indeed is only using 1TB of the 3, have you tried taking out the 2nd or 3rd drives to see if that causes it to stop working? You mentioned before you took a drive out earlier to verify that it was using eSATA... was that the first drive in the RAID array?


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## echo (Aug 18, 2007)

It's a 5 drive array. I put the drives in positions 1, 3 and 5 for best air flow. On separate occassions, I've taken out the drives in positions 1 and 5. Both caused the machine to freeze.


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## veryoldschool (Dec 10, 2006)

echo said:


> It's a 5 drive array. I put the drives in positions 1, 3 and 5 for best air flow. On separate occassions, I've taken out the drives in positions 1 and 5. Both caused the machine to freeze.


100 Gigs is reserved by the unit for "D*", but I have to wounder if the box really knows what 3 TB is. [reminds me of a motherboard without the right BIOS to read a larger hard drive].
Things to look at:
Setup recording with one drive check usage.
Setup recording with two drives and check usage.


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## 1948GG (Aug 4, 2007)

I too have read (and re-read a number of times) all the threads on adding eSATA drives to the HR20, and I'm surprised that the single (to me) basic question hasn't been asked: That is, what drive 'box' are you using.

The HR20 s/w 'expects' to see only ONE drive on the eSATA port, from what I understand, and 'arrays' need to 'present' themselves to the box as if they were a single drive. Folks who put a single drive seem to have the best results, and I think that's exactly what you are seeing, the HR20 see's only one drive. When you put in more than that, things get more than a bit shaky. 

There have been (again, in the eSATA threads) some success with certain array drivers (silicon), that appeared to work and then went *Poof* after working for awhile. Others (again, the >3TB ones) seem to be okay, but then no further reports from the poster. 

The array driver in your drive box needs to 'present' the array as if it were one drive, and there are controllers that 'presume' to do just that; the chip listed is the Silicon Image SIL4726, but again, not enough feedback on it. You can look that up and see if the box you got has that chip, or some other, or look up the spec on it (the SIL), which touts itself as a 'port multiplier' that make the array look like a single drive to the attached computer. 

At least, that's how things are 'working' (or not) at present. I'm hoping that very soon we'll get more s/w upgrades in this area, particularly before VOD rolls out to the masses, because at that point the base drive space will disappear if one blinks slowly! To me as well, 3GB is the real starting off point for decent storage!


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## Ken S (Feb 13, 2007)

Ignore most of this as VOS points out below...my reading comprehension skills are slipping.

What type of RAID array do you have setup? RAID 0? RAID 5? The Diag screens should tell you.

RAID 0 should give you the total of all three drives as one
RAID 5 should give you the total of two drives

There are other possibilities like RAID 1 where one of the drives would basically be ignored (or used as a swap in case of a failure). RAID 1 would give you the space of just a single drive.

So, for max space you want RAID 0. If you want some redundancy go with RAID 5...although I'm not sure how much redundancy would help with the HR20.


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## veryoldschool (Dec 10, 2006)

"I got an enclosure and put in three Hitachi 1 TB drives (3 TB total) and set them up in a RAID-0 array." From post #1


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## Ken S (Feb 13, 2007)

veryoldschool said:


> "I got an enclosure and put in three Hitachi 1 TB drives (3 TB total) and set them up in a RAID-0 array." From post #1


Oh, sure...like I'm going to read all the way to the end of the first line. 

Sorry about that.

If it's RAID 0 should be seen as one drive. Maybe someone at D could tell us if there is a cap on disk space...or perhaps the actual length of some of those recordings listed is much longer than listed?

Does the diag/controller program on the array give you any drive data if you plug it into a computer?

Also, is this an HR20-100 or 700. Has anyone done a large eSATA array on a 100 yet and reported here?


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## echo (Aug 18, 2007)

How do I find out if its a 100 or a 700?


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## Michael D'Angelo (Oct 21, 2006)

echo said:


> How do I find out if its a 100 or a 700?


Press the info button for 3 seconds and the info screen will come up and tell you what model it is.


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## Groundhog45 (Nov 10, 2005)

echo said:


> How do I find out if its a 100 or a 700?


Or look behind the trap door where the card is. It should tell you there.


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## DBordello (Dec 16, 2006)

I would try hooking the enclosure up to a computer. If you don't have an esata port you can buy a sata card fairly cheap. The computer will provide us more feedback. IE, does the OS see 1 drive or 3, what capacity does it believe it has. From there you can narrow down the culprit. 

Does the enclosure explicitly allow hot-swapping? It could be the esata device panicing when you pull the drive, not the hr20.


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## 1948GG (Aug 4, 2007)

Well, we still don't know 'what' enclosure we're all talking about... would be 'nice' to know which one.

But, it's been a couple months since I searched for something which explicitly (or even implicitly) said it would work with the HR20, so sent the google on it's way and I can up with this:

http://www.datoptic.com/cgi-bin/web.cgi?product=Sbox-R&detail=yes

Looks interesting, using that SIL4726 chip I was referencing in the last posting. Don't know what drives (manufacturer) they supply, but they do sell a non-populated box for $549. If they guarantee it's operation, it just may be the ticket.

FYI here is the unit I believe was referenced in one of the eSATA threads I looked up several months ago:

http://www.cooldrives.com/harasaiipomu.html

Echo, is this the box we're talking about (either one), or something else?


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## william8004 (Oct 6, 2006)

I was told my reply was inaccurate. Hence the edit.

I still stand by my statement that RAID 0 provides no data redundancy.


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## P Smith (Jul 25, 2002)

william8004 said:


> IMHO
> 
> I believe that RAID 0 is also called JBOD (just a bunch of disks). <..>


Wrong.


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## echo (Aug 18, 2007)

It is a 700.

And it's this enclosure:
http://www.cooldrives.com/fidrsaiihara.html

Although that other one you listed looks like it would have been a much better deal!! Kind of makes me mad because I emailed the tech guy at CoolDrives, told him exactly what I wanted to do with the enclosure, and he told me the one I ended up buying was the only one that would work. The one 1948GG posted looks like it would definitely have worked.

So I guess it's SR6600, not Silicon Image.

I'll hook it up to my computer tomorrow, see if the computer sees one array for 3 TB or not. Will post results tomorrow.

Thanks for all the comments so far.


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## P Smith (Jul 25, 2002)

$1300 for the device and no disks ! No way !


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## VegasDen (Jul 12, 2007)

william8004 said:


> I believe that RAID 0 is also called JBOD (just a bunch of disks).


RAID 0 is also known as a stripe set or striped volume. It splits data evenly across two or more disks (striped) with no parity information for redundancy. Storage space added to the array by each disk is limited to the size of the smallest disk.

JBOD, or "Just a Bunch Of Disks", is a popular method for combining multiple physical disk drives into a single virtual disk. JBOD uses two or more physical drives to create one logical drive. Disks of different sizes can be used.


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## 1948GG (Aug 4, 2007)

VegasDen said:


> JBOD, or "Just a Bunch Of Disks", is a popular method for combining multiple physical disk drives into a single virtual disk. JBOD uses two or more physical drives to create one logical drive. Disks of different sizes can be used.


Yep. I've got a JBOD array on a machine I use for video editing, in my IT room (variously known as a 'dining room' in most homes!). that I constructed some 5 years ago, right at the 'dawn' of sATA drives. Oh, for what I paid for those drives...! But lots of good use out of them, no hiccups, never have seriously thought about reformatting them to Raidx. But I always have the 'original' analog (or digital with DV) video tape if they ever do.

But I'm sure we are all looking for a 'certified' solution for the HR20, and that IF one actually is a 'known working solution' in that 3TB+ size range, that various credit cards across the country will simultaneously burst into flames all at once! Of course, DirecTV 'could' certify something out there...:eek2:


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## osultan (Feb 23, 2007)

With RAID 0, the array presents as a single disk to the host, so that should not be a problem. 

However, RAID 0 stripes your data across the disks in the array, so a recorded program may be split across all three of your component disks, which improves both read and write performance (the traditional reason for implementing RAID 0). This precludes you from randomly adding and removing disks from the array.

For what you are trying to accomplish, a JBOD type set-up might work better.

I would also wonder if the HR20 can fully address 3TB or allocate disk space efficiently (i.e. a cluster size type of issue). I don't know enough about the HR20 filesystem to venture a guess on that front.


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## william8004 (Oct 6, 2006)

P Smith said:


> Wrong.


I corrected my previous entry. I stand corrected. Next time please take the opportunity to enlighten me with new knowledge. You passed up an opportunity to teach me.


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## DBordello (Dec 16, 2006)

After looking at the enclosure it looks very advanced and should easily be able to do what he is asking. We'll see what the computer spits out. I really like the LAN administration feature.


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## william8004 (Oct 6, 2006)

P Smith said:


> Wrong.





VegasDen said:


> RAID 0 is also known as a stripe set or striped volume. It splits data evenly across two or more disks (striped) with no parity information for redundancy. Storage space added to the array by each disk is limited to the size of the smallest disk.
> 
> JBOD, or "Just a Bunch Of Disks", is a popular method for combining multiple physical disk drives into a single virtual disk. JBOD uses two or more physical drives to create one logical drive. Disks of different sizes can be used.


Thanks. I mis-spoke.

What are your thoughts on no data redundancy? Is it worth the extra space instead of using RAID 5?


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## Ken S (Feb 13, 2007)

william8004 said:


> I was told my reply was inaccurate. Hence the edit.
> 
> I still stand by my statement that RAID 0 provides no data redundancy.


That's correct...it basically just "stripes" the drives together.


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## P Smith (Jul 25, 2002)

william8004 said:


> Thanks. I mis-spoke.
> 
> What are your thoughts on no data redundancy? Is it worth the extra space instead of using RAID 5?


For regular ppl who need time shifting feature RAID-0 is the solution; if you in that business what require to KEEP recordings, then choose RAID-5, but you have to pay high price for that, plus for later purpose it will need to implement tape backup, as the 3 TB will be filled quickly in months counting HD volume.


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## Doug Brott (Jul 12, 2006)

P Smith said:


> For regular ppl who need time shifting feature RAID-0 is the solution; if you in that business what require to KEEP recordings, then choose RAID-5, but you have to pay high price for that, plus for later purpose it will need to implement tape backup, as the 3 TB will be filled quickly in months counting HD volume.


The high price for RAID-5 is not all that steep.

One extra drive is required and does not count toward available storage space
small delay in calculating the extra parity data, but this is generally negligible

As for implementing tape backup and filling 3 TB of HD, I would question that. Sure, if all you're doing is recording and recording everything you will reach the limit. However, that's true regardless of the size of the disk. At some point you will have to decide what you want to keep.

Personally, I have two HR20s with stock HDD. My habits keep me from ever reaching capacity. Hopefully folks that have 5x the capacity I do can do the same.


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## Ken S (Feb 13, 2007)

The low-price of RAID 5 is that it's far less likely to suffer from a bad write and crash the HD causing the HR20 to reformat it. Plus if one drive goes bad you can swap another in.
I'd suggest anyone that is investing in keeping 3TB of TV content must lend some importance to that content and want to protect it.
Now, if you really want speed and security...there's always RAID 10


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## P Smith (Jul 25, 2002)

Doug, "The high price for RAID-5 is not all that steep" - I think it opposite. Look, ppl always complain after $3-$5 price increase for programming, I'm not counting complain about a price of equipment and service - but it in range $ to $$$. Here we are talking about STEEP increase - $$$$ for 'smart' enclosure and disks - 5x $$$. 
Nay, you missed the point of HIGH price for the luxury to have BIG storage in RAID-5 !


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## 1948GG (Aug 4, 2007)

P Smith said:


> Doug, "The high price for RAID-5 is not all that steep" - I think it opposite. Look, ppl always complain after $3-$5 price increase for programming, I'm not counting complain about a price of equipment and service - but it in range $ to $$$. Here we are talking about STEEP increase - $$$$ for 'smart' enclosure and disks - 5x $$$.
> Nay, you missed the point of HIGH price for the luxury to have BIG storage in RAID-5 !


It's all 'relative'. I paid almost $1K per disc 5 years ago for 200GB first gen. sATA Seagates (sATA 1 speed!); now that you've picked your jaws off the floor, think that 'today' high capacity perpendicular drives in the 750GB-1TB range are going for close to $200... and if you think about it for more than a second, you weep! So in the scheme of things, that additional space for RAID5 is a pretty small percentage cost wise of the total.

But the ultimate thing we're trying to get at here, is the 'smarts' of the disc controller in the box, and how that interacts (or doesn't) with the HR20. Maybe we'll be closer to an answer in 2-3 days.


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## Doug Brott (Jul 12, 2006)

Agreed, it's all relative. Certainly the actually $ cost will be higher the more HDD capacity you add to the system (whatever the means). The level that folks choose is different for each person.


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## 1948GG (Aug 4, 2007)

I got around to trying to organize a few of my notes on this, and came up with this (earlier this year) thread on the SIL4726 box:

http://www.dbstalk.com/showthread.php?t=74560&highlight=4726

It's been awhile since an update on that thread, don't know if it's still running okay. Like most of these discussions, though, it slides into talking about single-drive solutions. I emailed the originator, maybe he can add something to the discussion.


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## echo (Aug 18, 2007)

So far I've been unsuccessful in connecting the enclosure to my computer. I've tried connecting both the ethernet and USB cables and neither is working. Can't find it anywhere in My Computer or in network connections. I have a 2Wire router and I can see the enclosure when I open the router settings page, but that's it. I can't access it. Tried everything I can think of including different cables. Also, it came with a CD so I thought maybe there were drivers on the CD but there aren't. CD is basically not helpful at all. 

The more I've thought about it, based on the programs I have recorded (as listed in my first post) even if the HR20 were only seeing 1 of the 3 drives, it still seems like I should have more than 90% free space on a 1 TB drive....

Instead, it seems like the HR20 is reporting free space based on the internal drive or something. 

I've triple checked the settings and it says it's programmed as RAID 0, not a JBOD.


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## P Smith (Jul 25, 2002)

OK, for final nail to a coffin in sub-discussionn of advantage of RAID-5, please post total price for your external storage setup:
- an enclosure
- disks
- S/H and tax.

Thanks.


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## micky76ag (Feb 18, 2007)

echo said:


> Can't find it anywhere in My Computer or in network connections.


I don't lease a HR20 yet, and I have not read all the eSATA threads. But, once you plug the enclosure into the HR20, it gets formatted to work with the DVR, correct?

Maybe this formatting is not compatible with windows -- might have to reformat in a windows format in order for your computer to see the RAID drive.


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## Doug Brott (Jul 12, 2006)

P Smith said:


> OK, for final nail to a coffin in sub-discussionn of advantage of RAID-5, please post total price for your external storage setup:
> - an enclosure
> - disks
> - S/H and tax.
> ...


Sorry P Smith, I don't think there is a coffin involved in this one. Different strokes for different folks. For some, dollars are the overriding concern (in my case, I didn't even go the eSATA route). For others, the concern is having a bit of redundancy.

A RAID-5 solution is inherently more costly from a dollar perspective. A RAID-0 solution is inherently more risky. Either choice comes with a cost, so each person has to weigh these factors when making a decision.


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## veryoldschool (Dec 10, 2006)

My understand of RAID was for corporate mission critical data.
Folks this is only TV programs.
While we have "geek" in us, it's only TV and I have a very hard time watching a rerun of anything.


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## Doug Brott (Jul 12, 2006)

VOS, there are different types of RAIDs .. (I'm sure you know this, though).

The most relevant in this situation are RAID-0, RAID-5 and conceivably RAID-10.

*RAID-0* takes all of the drives and stripes them essentially giving the a full capacity of the sum of all of your drives.

*RAID-5* has an extra disk that essentially provides a checksum for all of the other drives. Typically, the amount of usable disk space is the sum of all of the drives minus one drive.

*RAID-10* is essentially two sets of RAID-0 configurations (as above) with the second set a mirror of the first set.

In both RAID-5 and RAID-10 situations, you can have a HDD failure and by simply replacing the HDD lose no data .. obviously the cost would be higher.

In a RAID-0 situation, if you lose any HDD then you lose everything.

both RAID-0 and RAID-10 solutions will provide the quickest data reads and writes (multiple moving parts vs a single moving part), but in the video application use, it is unlikely that a RAID-0/RAID-10 solution is better than a RAID-5 solution for speed.

So, the real choice in the video arena would be a RAID-0 or a RAID-5 solution. The bottom-line difference is that RAID-0 gives you more capacity and RAID-5 gives you more reliability given the same number of HDD.

The more you spend in dollars (in either solution), the more capacity that becomes available to you.


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## veryoldschool (Dec 10, 2006)

With ten years of playing with RAID-5, I do understand.
I can't seem to fill the internal drive much more than 50% [and that's with the Discovery Planet Earth programs that I have yet tot watch for a second time].
I know this is mostly "me", but very few shows/movies are good enough to watch a second time and be entertained. I wish they would be intriguing enough to be able to watch more than once and still find some part interesting enough after the "first pass".


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## John4924 (Mar 19, 2007)

1948GG said:


> ......
> 
> FYI here is the unit I believe was referenced in one of the eSATA threads I looked up several months ago:
> 
> ...


FWIW, I tried to order one of these several months ago, and I received a note back from the vendor saying they were out of stock. And I have not heard from them since then. So I am not even sure these can be purchased.

I would be interested if someone can purchase one of these and let us know if this works.

Cheers,
John


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## Smuuth (Oct 4, 2005)

veryoldschool said:


> My understand of RAID was for corporate mission critical data.
> Folks this is only TV programs.
> While we have "geek" in us, it's only TV and I have a very hard time watching a rerun of anything.


You are correct in your understanding of the original reason for RAID. However, RAID 0 was not one of the original RAID levels because it provides _zero data redundancy._ The primary advantage of RAID 0 is higher bandwidth.


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## John4924 (Mar 19, 2007)

veryoldschool said:


> With ten years of playing with RAID-5, I do understand.
> I can't seem to fill the internal drive much more than 50% [and that's with the Discovery Planet Earth programs that I have yet tot watch for a second time].
> I know this is mostly "me", but very few shows/movies are good enough to watch a second time and be entertained. I wish they would be intriguing enough to be able to watch more than once and still find some part interesting enough after the "first pass".


VOS, just one more post to 8,000! :lol:


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## veryoldschool (Dec 10, 2006)

Smuuth said:


> You are correct in your understanding of the original reason for RAID. However, RAID 0 was not one of the original RAID levels because it provides _zero data redundancy._ The primary advantage of RAID 0 is higher bandwidth.


If I remember right the "advantage" only came with fairly high priced RAID controllers.
Most of the controllers while having a RAID chip still didn't perform much [any] faster than a software RAID. Things may have changed in the years since these tests were done though.


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## P Smith (Jul 25, 2002)

Oops. HW RAID is always faster then OS implementation of it. Been that way more then 17 years on my memory. ')


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## echo (Aug 18, 2007)

I'm gonna reformat the whole array, see if maybe it just didn't get formatted correctly the first time. A lot of good comments about RAID 5 and RAID 10. Which is better? Seems like some people favor RAID 5 and some RAID 10...


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## Ken S (Feb 13, 2007)

echo said:


> I'm gonna reformat the whole array, see if maybe it just didn't get formatted correctly the first time. A lot of good comments about RAID 5 and RAID 10. Which is better? Seems like some people favor RAID 5 and some RAID 10...


RAID 5 requires a minimum of 3 drives and you get the total of two of them. It would be fine for this application

RAID 10 requires a minimum of 4 drives and you get the total of two of them. It would be overkill in this situation.


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## Doug Brott (Jul 12, 2006)

Personally, I see absolutely no point in going RAID-10 for video storage. I really don't think there are any speed issues to need a RAID-0/RAID-10 configuration vs. a RAID-5 configuration and a RAID-10 will invariably require more HDD than a RAID-5 would.

I'd say stick with RAID-0 for optimized capacity and RAID-5 for optimized reliability on the HR20 eSATA setups.


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## veryoldschool (Dec 10, 2006)

Doug Brott said:


> Personally, I see absolutely no point in going RAID-10 for video storage. I really don't think there are any speed issues to need a RAID-0/RAID-10 configuration vs. a RAID-5 configuration and a RAID-10 will invariably require more HDD than a RAID-5 would.
> 
> I'd say stick with RAID-0 for optimized capacity and RAID-5 for optimized reliability on the HR20 eSATA setups.


+1


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## DBordello (Dec 16, 2006)

Before you do anything, I'd like to see what the computer is reporting. Since I offered the suggestion I better follow up with it. I can guarantee that the filesystem the HR20 put on the drive(s?) windows does not know how to mount, but it will see the drives, just not through my computer. 

Try hooking it back up USB (this can't easily be done via the ethernet port). Under control panel -> Administrative ... there should be some sort of drive manager (sorry, going by memory, haven't used windows in some time). It should show what drives are connected, how large each partition is, etc. It should see a USB drive with 1TB/3TB of unrecognized space. 

This should determine if the enclosure is working properly. If you are bored you can reformat the drive to NTFS and play with it. 

-dan


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## DBordello (Dec 16, 2006)

I just loaded a virtual machine of Windows XP. What you are looking for is under control panel -> Administrative Tools -> Computer Management -> Disk Management. You should see another volume (won't have a drive letter) and you should be able to determine the size from there.

-dan


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## Doug Brott (Jul 12, 2006)

I believe that the File System on the HDD is some sort of hybridized UNIX style file system. You can determine the sizes, but that's about it. I'm not sure why folks would want to reformat it. That would erase all of the video files.


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## P Smith (Jul 25, 2002)

Doug Brott said:


> I believe that the File System on the HDD is some sort of hybridized UNIX style file system. You can determine the sizes, but that's about it. I'm not sure why folks would want to reformat it. That would erase all of the video files.


Just check this thread/post http://dbstalk.com/showthread.php?p=1016959&highlight=xfs#post1016959


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## ShawnL25 (Mar 2, 2007)

I have a similar set-up and what I did to insure that I was getting maximum use of my drives I recorded every program on HDNET Movies in mepeg 2 hd I expected about 34 hrs per 250 gb based on HR10-250, I found that at 50% I had 94hrs 1tb I am currently at 1% available and I have 236hrs 2tb recorded HD all mpeg2 from HBO Showtime and HDnet Movies, clearly 94 is not 50% of 236 so I have concluded that the percentages do not necessarily work. I would try this test it take about a week you should end up with around 330hrs mpeg 2 HD of course we will be recording mostly mpeg4 soon so I would expect that number to go from 34 to 50.


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## micky76ag (Feb 18, 2007)

Doug Brott said:


> I'm not sure why folks would want to reformat it. That would erase all of the video files.


Good point. I think I was the first to mention reformatting, sorry.

But, I wasn't really suggesting a reformat, just saying the drive probably could not be recognized by windows without a reformat.

It was an attempt to explain why he wasn't seeing the drive under "My Computer."

Sorry for the confusion.


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## jpoet (Feb 9, 2007)

P Smith said:


> Oops. HW RAID is always faster then OS implementation of it. Been that way more then 17 years on my memory. ')


Not anymore. At least under Linux.

Modern CPU's are fast enough, and Linux's implementation is efficient enough, that software raid is actually faster than most of the hardware based raid solutions.

One advantage of hardware RAID, however, is if the controller has it's own battery backup. In theory, the hardware RAID card can flush out any pending data when the computer comes back up -- after a crash.

John


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## P Smith (Jul 25, 2002)

jpoet said:


> Not anymore. At least under Linux.
> 
> Modern CPU's are fast enough, and Linux's implementation is efficient enough, that software raid is actually faster than most of the hardware based raid solutions.
> 
> ...


I'd like to read those studies. Real one, not just linuxoids claims.


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## echo (Aug 18, 2007)

Good news!! The reformat worked. Who knows what was wrong with it before, but a complete reformat definitely fixed the free space reporting issue.

3 drives in RAID 5, so that means 2 TB of recording space (if I've followed everything correctly).

I have recorded 22 hours in HD and still have 93% available. Much better!! 

Two more Hitachi drives on the way so I can run 5 drives in RAID 5. Will that give me 3 TB or 4 TB of recording space?

Thanks to everyone for the help and tips. I've learned a lot and a lot of good came out of this. I'm now running a RAID 5 array with redundancy instead of the riskier RAID 0.

I'll keep everyone updated on the 5 TB array.


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## Ken S (Feb 13, 2007)

echo said:


> Good news!! The reformat worked. Who knows what was wrong with it before, but a complete reformat definitely fixed the free space reporting issue.
> 
> 3 drives in RAID 5, so that means 2 TB of recording space (if I've followed everything correctly).
> 
> ...


That should give you 4TB of space.


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## Doug Brott (Jul 12, 2006)

Hmmm .. Will the HR20 recognize the additional space once it has been added?


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## P Smith (Jul 25, 2002)

RAID-5 on N disks (equal size) will give you N-1 total usable size.


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## Michael D'Angelo (Oct 21, 2006)

Doug Brott said:


> Hmmm .. Will the HR20 recognize the additional space once it has been added?


I believe you have to reformat the hard drive again.


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## P Smith (Jul 25, 2002)

Doug Brott said:


> Hmmm .. Will the HR20 recognize the additional space once it has been added?


Sure not, expect reformatting.


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## Doug Brott (Jul 12, 2006)

BMoreRavens said:


> I believe you have to reformat the hard drive again.


That's what I was thinking.


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## veryoldschool (Dec 10, 2006)

Doug Brott said:


> That's what I was thinking.


If it isn't formated, then it isn't part of the array.


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## Ken S (Feb 13, 2007)

Some RAID 5 Controllers can add a new drive into the Array without having to reformat the whole thing.


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## P Smith (Jul 25, 2002)

Ken S said:


> Some RAID 5 Controllers can add a new drive into the Array without having to reformat the whole thing.


Actually it is not RAID controller but NAS. Please keep terminology straight.


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## MarkV (Aug 19, 2007)

Has anyone confirmed that the filesystem supported by the HR20 will reach 3.5TB ? Will it exceed 2TB ?

Any comments on the Silverstone DS351 vs the CoolDrives harasaiipomu? DS351 is more expensive but is available (unclear of the harasaiipomu is in stock) and it integrates well with a HT rack. Should one expect equivalent functionality ?

Thanks,
Mark


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## P Smith (Jul 25, 2002)

MarkV said:


> Has anyone confirmed that the filesystem supported by the HR20 will reach 3.5TB ? Will it exceed 2TB ?
> 
> Any comments on the Silverstone DS351 vs the CoolDrives harasaiipomu? DS351 is more expensive but is available (unclear of the harasaiipomu is in stock) and it integrates well with a HT rack. Should one expect equivalent functionality ?
> 
> ...


Please search for 3.75 TB thread.


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## Ken S (Feb 13, 2007)

P Smith said:


> Actually it is not RAID controller but NAS. Please keep terminology straight.


P Smith,

I'm missing something here. What does Network Storage have to do with the abilities of a RAID controller? Actually, what does NAS have to do with the HR20 at all?


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## P Smith (Jul 25, 2002)

OK, if you remember someone pointed to same ability to resize partition without rebuild it, but what it come to check what 'controller' it was, appeared it was NAS box.
So, if you will tell me a maker and a model, then we will continue.


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## Doug Brott (Jul 12, 2006)

Yes, some RAID controllers and setups will let you grow the storage (i.e. the File System). It is unlikely, however, that the HR20 supports that and hence my question. I didn't want echo to think that the 3-disk configuration he had could be expanded to a 5-disk configuration while saving his recordings. If you have to reformat, then you will lose the recordings.


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## Ken S (Feb 13, 2007)

Doug Brott said:


> Yes, some RAID controllers and setups will let you grow the storage (i.e. the File System). It is unlikely, however, that the HR20 supports that and hence my question. I didn't want echo to think that the 3-disk configuration he had could be expanded to a 5-disk configuration while saving his recordings. If you have to reformat, then you will lose the recordings.


Doug,

I don't know enough about the File System they're using to even guess if it would work. If I did it...I would make sure the HR20 was turned off though .


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## Ken S (Feb 13, 2007)

P Smith said:


> OK, if you remember someone pointed to same ability to resize partition without rebuild it, but what it come to check what 'controller' it was, appeared it was NAS box.
> So, if you will tell me a maker and a model, then we will continue.


Ahh...I wasn't thinking of that at all. I was thinking of the Compaq servers I had a while back. Can't remember what controller we were using. I'm pretty sure that some of the 3Ware cards will do it...only on RAID 5 and, maybe 6, of course.


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## 1948GG (Aug 4, 2007)

Doug Brott said:


> I didn't want echo to think that the 3-disk configuration he had could be expanded to a 5-disk configuration while saving his recordings. If you have to reformat, then you will lose the recordings.


I think that at 22 hrs. of HD recordings, that all Echo did was, once it appeared 'alive', was simply start recording (probably 2 channels at once) of HD while he slept. At least, that's what I would sure do!

But lets have a reality check here real quick (reality as in $$$):

Array Box cost (SR6600): $1400

5 Hitachi 1TB Drives: $350 ea. (best price Pricegrabber) for $1750 total

Grand Total: ~$3150

So, that's the bottom line, if it all works after plugging in the final 2 drives (4TB total usable space). If one wanted to trim in down a bit with 750GB drives (like Seagate), the total would be down to $2300 (and total usable capacity would be 3TB). Of course, that doesn't include what DirecTV 'sets aside' (supposedly 100gb) but at this amount of space that's extremely 'minor'.


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## houskamp (Sep 14, 2006)

1948GG said:


> I think that at 22 hrs. of HD recordings, that all Echo did was, once it appeared 'alive', was simply start recording (probably 2 channels at once) of HD while he slept. At least, that's what I would sure do!
> 
> But lets have a reality check here real quick (reality as in $$$):
> 
> ...


That's an understament! :lol:


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## echo (Aug 18, 2007)

Yes, I will reformat the whole thing once I get the other two drives. I will post after a few weeks of operation and let everyone know if its working.

Here's something I don't understand though...So 5 disks in RAID 5 results in 4 disks of usable space, and the other disk is for backup? How exactly is 1 disk able to back up 4 disks of data?


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## veryoldschool (Dec 10, 2006)

echo said:


> Yes, I will reformat the whole thing once I get the other two drives. I will post after a few weeks of operation and let everyone know if its working.
> 
> Here's something I don't understand though...So 5 disks in RAID 5 results in 4 disks of usable space, and the other disk is for backup? How exactly is 1 disk able to back up 4 disks of data?


The fifth disk is called parity. Since the first four are striped, look at it this way: it writes a block to each dish and then "adds up" what the numbers of those blocks are and then writes this to the last disk. If a disk fails, and then replaced with a "blank", in the rebuilding utility, it adds up the disks left and then compares it to the parity disk. The difference is then written to the blank disk so it now matches.
It does this for every block until everything matches.


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## echo (Aug 18, 2007)

Ha! Well, I never said it was economical....

Thanks for the explanation of RAID 5 oldschool.


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## P Smith (Jul 25, 2002)

Hey Doug ! 
"The high price for RAID-5 is not all that steep." Remember ?
Tell me about not all that steep price again .
Don't forget to add taxes and S/H. 



1948GG said:


> I think that at 22 hrs. of HD recordings, that all Echo did was, once it appeared 'alive', was simply start recording (probably 2 channels at once) of HD while he slept. At least, that's what I would sure do!
> 
> But lets have a reality check here real quick (reality as in $$$):
> 
> ...


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## Doug Brott (Jul 12, 2006)

P Smith said:


> Hey Doug !
> "The high price for RAID-5 is not all that steep." Remember ?
> Tell me about not all that steep price again .
> Don't forget to add taxes and S/H.


Ah, but we were comparing it to a RAID-0 implementation .. both are too steep for me. RAID-0 with the same amount of usable disk space would be 1 HDD lower in cost, so subtract $350 .. less than 10% of the total? The cost is roughly comparable.


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## Ken984 (Jan 1, 2006)

Here is a really good price on a Raid5 box, with drives! I have not ordered one but it looks like it has all the right stuff, anyone have any experience with this?
http://www.buy.com/retail/product.asp?sku=204389695&adid=17653&dcaid=17653


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## jpoet (Feb 9, 2007)

Ken S said:


> Ahh...I wasn't thinking of that at all. I was thinking of the Compaq servers I had a while back. Can't remember what controller we were using. I'm pretty sure that some of the 3Ware cards will do it...only on RAID 5 and, maybe 6, of course.


The RAID controller in the external box probably *can* grow the raid, but then the filesystem must also be "grown" and that would be up to the HR20.

John


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## Doug Brott (Jul 12, 2006)

jpoet, exactly right. Some operating systems can handle growth, others can't. It is doubtful that the HR20 will ever be fitted with this feature because of the nature of what it does.


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## Ken S (Feb 13, 2007)

Doug Brott said:


> jpoet, exactly right. Some operating systems can handle growth, others can't. It is doubtful that the HR20 will ever be fitted with this feature because of the nature of what it does.


There's one quick way to tel.


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## P Smith (Jul 25, 2002)

And I'm guarantee you will see the expanded storage will be reformatted.


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## ejkuhl (Jun 11, 2007)

veryoldschool said:


> The fifth disk is called parity. Since the first four are striped, look at it this way: it writes a block to each dish and then "adds up" what the numbers of those blocks are and then writes this to the last disk. If a disk fails, and then replaced with a "blank", in the rebuilding utility, it adds up the disks left and then compares it to the parity disk. The difference is then written to the blank disk so it now matches.
> It does this for every block until everything matches.


Close but not exactly. There is not a dedicated parity drive in RAID 5. The parity bits are distibuted across all drives. RAID 4 has dedicated parity disk but this implementation has bottlenecks and is rarely used.


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## veryoldschool (Dec 10, 2006)

ejkuhl said:


> Close but not exactly. There is not a dedicated parity drive in RAID 5. The parity bits are distibuted across all drives. RAID 4 has dedicated parity disk but this implementation has bottlenecks and is rarely used.


That was the way it was explained to me by a couple of instructors. Maybe it isn't "exactly" that way and they just used it to have me understand the concept. I don't know, just that it does works.


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## Doug Brott (Jul 12, 2006)

veryoldschool said:


> That was the way it was explained to me by a couple of instructors. Maybe it isn't "exactly" that way and they just used it to have me understand the concept. I don't know, just that it does works.


VOS, the way ejkuhl explains it is really correct. The real way RAID-5 works is just too confusing to talk about. A 'parity disk' discussion usually results in everyone understanding exactly what needs to be understood for the discussion. :grin:


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## veryoldschool (Dec 10, 2006)

Doug Brott said:


> VOS, the way ejkuhl explains it is really correct. The real way RAID-5 works is just too confusing to talk about. A 'parity disk' discussion usually results in everyone understanding exactly what needs to be understood for the discussion. :grin:


OK, thanks.


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## P Smith (Jul 25, 2002)

I shouldn't wish this to anyone, but if you'll spend a week reading sectors from dead RAID-5 disks attempting to restore critical data, what was on there, but tape backup failed, then the parity sectors will be seen in your night dreams for long period of time.


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## Thaedron (Jun 29, 2007)

Doug Brott said:


> *RAID-10* is essentially two sets of RAID-0 configurations (as above) with the second set a mirror of the first set.


FYI... I've always understood that this is referred to as RAID 1+0, rather than RAID 10. The use of the + indicates that it is the combination of RAID 0 and RAID 1.


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## Doug Brott (Jul 12, 2006)

Thaedron said:


> FYI... I've always understood that this is referred to as RAID 1+0, rather than RAID 10. The use of the + indicates that it is the combination of RAID 0 and RAID 1.


Yes .. It has, though, morphed into RAID-10 .. easier to say


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## Ken S (Feb 13, 2007)

Thaedron said:


> FYI... I've always understood that this is referred to as RAID 1+0, rather than RAID 10. The use of the + indicates that it is the combination of RAID 0 and RAID 1.


 RAID 0+1: Striped Set + Mirrored Set (4 disk minimum; Even number of disks) provides fault tolerance and improved performance but increases complexity. The key difference from RAID 1+0 is that RAID 0+1 creates a second striped set to mirror a primary striped set. The array continues to operate with one or more drives failed in the same mirror set, but if two or more drives fail on different sides of the mirroring, the data on the RAID system is lost.

RAID 1+0: Mirrored Set + Striped Set (4 disk minimum; Even number of disks) provides fault tolerance and improved performance but increases complexity. The key difference from RAID 0+1 is that RAID 1+0 creates a striped set from a series of mirrored drives. The array can sustain multiple drive losses as long as no two drives lost comprise a single pair of one mirror.

Now, should we start talking about RAID 5+1 and RAID 6 

P Smith,

Even worse was living through that rebuild and then a Netware rebuild and then the re-index of some Advanced Revelation databases. never again...nope...never again.

My first time having fun with disk sectors was piecing together a shattered file on a Commodore 64/128 floppy disk. I had to find each sector and then edit the block with the number for the next sector. It's amazing what a deadline on a law school paper will drive you to.


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## Doug Brott (Jul 12, 2006)

Ken S said:


> Now, should we start talking about RAID 5+1 and RAID 6


:lol:

For eSATA solutions on the HR20, just keep it simple ..

RAID-0 for optimized capacity

or

RAID-5 for optimized reliability


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## Ken S (Feb 13, 2007)

Doug Brott said:


> :lol:
> 
> For eSATA solutions on the HR20, just keep it simple ..
> 
> ...


Doug,

I was kidding 

Actually, there is one other thing we should throw into the mix....the more drives you have running the more heat you produce and the more noise they'll make.


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## Doug Brott (Jul 12, 2006)

Ken S said:


> Doug,
> 
> I was kidding
> 
> Actually, there is one other thing we should throw into the mix....the more drives you have running the more heat you produce and the more noise they'll make.


I know it was a joke .. I tried to laugh along  Is this better?

:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

True, the more drives you have, the more heat you generate, the more electricity you use and the more noise you hear. I guess it costs more than just dollars ..

I plan on sticking to a stock receiver. I figure if the disk is full then it's time to stop recording anyway .


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## P Smith (Jul 25, 2002)

Ken S said:


> <..>
> 
> Even worse was living through that rebuild and then a Netware rebuild and then the re-index of some Advanced Revelation databases. never again...nope...never again.
> 
> My first time having fun with disk sectors was piecing together a shattered file on a Commodore 64/128 floppy disk. I had to find each sector and then edit the block with the number for the next sector. It's amazing what a deadline on a law school paper will drive you to.


I had to restore mirror (2x80 GB) on Netware 2.15 long time ago, but that time I wrote my own program for reading/comparing sectors, that SW ran from DOS floppy and it was big relief comparing to later broken Adaptec RAID SCSI 7x36 GB with Windows NT 4.0 data volume.
Your floppy restore would be simple walk compare to those disks.


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## 1948GG (Aug 4, 2007)

Doug Brott said:


> I plan on sticking to a stock receiver. I figure if the disk is full then it's time to stop recording anyway .


The biggest reason why (this is me) wants much larger storage on the machine, is a number of reasons, and why simply erasing is not going to work (in either the short term or long term).

The VOD is one thing, but the #1 is the pitiful state of the HD DVD 'wars' and downright abysmal HD DVD players and software. The stage of HD DVD development is tracking right along the same path as standard def DVD's were in the late 90's; poor transfers, lack of standardized encoding s/w, players lacking audio compatabity (like Dolby TrueHD and DTS-HD), the list goes on and on, not to talk about pricing. Again, if they continue to follow the same 'learning curve' as the original DVD, it'll be about 5 more years before things start to get together (both figuratively and sans the format war).

During the next 5 years, the best (and only) way to 'sample' the HD wares is by the HD channels. Since virtually every prime time television series is in HD now, they are included along with movies. Large capacity DVR's are the only solution, to bridge the gap.

Hopefully, this will be solved by the end of this year, the faster the better.


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## Ken S (Feb 13, 2007)

1948GG said:


> The biggest reason why (this is me) wants much larger storage on the machine, is a number of reasons, and why simply erasing is not going to work (in either the short term or long term).
> 
> The VOD is one thing, but the #1 is the pitiful state of the HD DVD 'wars' and downright abysmal HD DVD players and software. The stage of HD DVD development is tracking right along the same path as standard def DVD's were in the late 90's; poor transfers, lack of standardized encoding s/w, players lacking audio compatabity (like Dolby TrueHD and DTS-HD), the list goes on and on, not to talk about pricing. Again, if they continue to follow the same 'learning curve' as the original DVD, it'll be about 5 more years before things start to get together (both figuratively and sans the format war).
> 
> ...


That's a very good point...and with the latest announcement it's only getting worse. I fear we're going to need another whole Christmas season (2008) before there's enough market adoption of one or the other to make it clear who wins.


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## erp2863 (Aug 24, 2007)

Has anyone with a RAID5 setup tried replacing one of the drives and re-building the array? I'm wondering if the HR20 will recognize it as the original array and continue or if it looks at it like a new volume and formats the array? Would kind of kill the whole reason for using RAID5.

Anyone with a RAID5 with minimal recordings stored willing to give it a try?

Thanks,
Eric


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## P Smith (Jul 25, 2002)

Any HW RAID by definition transparent for a host - nothing to worried !


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## Doug Brott (Jul 12, 2006)

I'd have to agree with P Smith on this one .. If it doesn't work then you've got the wrong RAID hardware.

Keep in mind, thought that RAID0 would not have that protection (of course).


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## Tom Robertson (Nov 15, 2005)

Raid is _usually_ and _mostly_ transparent to the host but not completely.

The small nitpick case: usually there is host software to monitor the status of the RAID, so it can't be completely transparent (but that is purely semantics.)

The bigger case, many times (tho becoming less frequent) you need that same monitoring software to add a new drive to an array and rebuild the RAID. Normally this can be done entirely with the host fully operational, tho at slightly reduced capacity during the rebuild.

Since the HR20 does not seem to have any connection to particular RAID controllers, the RAID controllers needs to be controlled via a front panel or taken to a PC. Something to consider when purchasing an array right now.

Cheers,
Tom


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## P Smith (Jul 25, 2002)

Ehh, Tom would we come to professional discussion about RAID and servers now ? 

He got what he need to know in the particular setup: HR20 and an enclosure with HW RAID-5. So, everything set and in case of failure HR20 will not affected and replacing failed HDD will follow rebuild RAID-5 by the enclosure HW[FW].


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## erp2863 (Aug 24, 2007)

Thanks guys! I've got some more testing to do before I'm comfortable with how the HR20 treats external storage. In the mean time, here are a few teaser shots of what I'm working on.... you can call it my alpha version... have a new case coming next week along with 2 more drives so I can start the 1.2Tb RAID-5 beta version...

800gb RAID-0 "VCR" with eSATA


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## CCarncross (Jul 19, 2005)

Ahhh, the old Mits DVR.....


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## P Smith (Jul 25, 2002)

Don't forget mount a couple fans (IN and OUT) !


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## erp2863 (Aug 24, 2007)

It ran last night for 9 hours recording DiscoveryHD. Showed 92% remaining of the 800gb. Not too shabby. The RAID controller I'm using was extremely warm, the hard drives were about the same as in my PC. I'll have to look into cooling strategies.

The fan from the PSU was a little louder than I wanted, might look into a fanless PSU. I couldn't hear the hard drives working, so I'm happy with that.


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## erp2863 (Aug 24, 2007)

For you RAID experts out there, what would be your suggested chunk/stripe size for a RAID5 configuration with respect to this PVR application? My minimum is 8kb and the max is 128kb. The documentation I have from the controller suggests the max for media storage applications.

Will be testing/proving the RAID5 re-build capability on the HR20 tonight.

Thanks!


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## Bly (Jul 9, 2007)

Is anyone sure the HR20 will support over 2 TB? I assume the OS use on this is Linux and the file system is most likely ext3? (Just guessing, I don't know)

So if block size was set to 1k the limit of ext3 is 2TB.

Most Likely: If the block size is 4k then we have a limit of 16TB.

Has anyone tried to mount a formated drive in Linux to see file system and block size?


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## P Smith (Jul 25, 2002)

erp2863 said:


> For you RAID experts out there, what would be your suggested chunk/stripe size for a RAID5 configuration with respect to this PVR application? My minimum is 8kb and the max is 128kb. The documentation I have from the controller suggests the max for media storage applications.
> 
> Will be testing/proving the RAID5 re-build capability on the HR20 tonight.
> 
> Thanks!


Video part would be better with 2 MB chunks, but in your case its out of options.


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## P Smith (Jul 25, 2002)

Bly said:


> Is anyone sure the HR20 will support over 2 TB? I assume the OS use on this is Linux and the file system is most likely ext3? (Just guessing, I don't know)
> 
> So if block size was set to 1k the limit of ext3 is 2TB.
> 
> ...


It has beed done and posted here.


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## rekoil (Aug 10, 2007)

JBOD (Just a Bunch Of Disks) - multiple drives are aggregated into a single logical drive, but are written "linearly" - one drive at a time. Simplest form of drive aggregation. No speed gains, no redundancy.
RAID 0 - "striped" mode - logical sectors are "spread" between the physical drives in a round-robin fashion, so that reads and writes are spread across the disks, giving you both a performance and capacity boost. Downside is no redundancy.
RAID 1 - "mirrored" mode - all drives get the same data written to them. This is strictly for redundancy, there are no performance or capacity gains. 
RAID 5 - "stripe + parity" - this is the most complex. The logical sectors are spread between the drives a la RAID 0, but one drive gets a "parity sector" written to it, which is a checksum based on the data written to the other disks. In the event of a single drive failure, the parity sector can be used to reconstruct what was on the failed disk, so the system can operate after removing/shutting down the failed disk. Replace the drive and the system will "reconstruct" the original disks data onto the replacement drive.


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## Doug Brott (Jul 12, 2006)

erp2863 said:


> For you RAID experts out there, what would be your suggested chunk/stripe size for a RAID5 configuration with respect to this PVR application? My minimum is 8kb and the max is 128kb. The documentation I have from the controller suggests the max for media storage applications.
> 
> Will be testing/proving the RAID5 re-build capability on the HR20 tonight.
> 
> Thanks!





P Smith said:


> Video part would be better with 2 MB chunks, but in your case its out of options.


Yeah .. for video I'd say make the stripe size as big as possible.


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## Doug Brott (Jul 12, 2006)

rekoil,

For the eSATA applications on the HR20 there really are only two choices that make sense (well three if are only using a single drive which would technically be JBOD ).

For multi-disk configurations:

If capacity is most important to you - RAID0

If reliability is most important to you - RAID5

Any other RAID configuration should only be considered by folks that have lots of money and lots of interest in tweaking the last 2% of the problem.


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## erp2863 (Aug 24, 2007)

Thanks for the info guys. I made the mistake of thinking my controller can do RAID5. It is my host adapter that can. I can only setup RAID 0, 1, 1+0. Doh!

So I figured I could still test the handling of rebuilt RAID arrays by setting up a RAID1 with 2 of drives. It is currently recording 2 channels. I'll let it run until tonight, swap out one of the drives with a 3rd drive and rebuild the array and see how the HR20 responds. If the recordings are still accessable on the HR20, then I'll be somewhat happy. Unfortunately the controller I can use for RAID5 is 2x the cost of my current one.

From the responses in the Tenbox thread, I'm now wondering how many people are truly interested in having built-in redundancy and an enclosure that fits well with other AV components? Or are most people interesting in maximum storage size?


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## Vor (Jul 5, 2007)

Doug Brott said:


> If capacity is most important to you - RAID1


<psst> RAID0.

RAID1, while being the lowest capacity, does have some advantage over RAID5 in reliability. With a complete mirror, if you lose a drive it just keeps going, while with RAID5 you're usually in a reduced performance mode while the controller has to calculate the missing data, and more reduced performance when the drive is replaced and parity has to be recalculated.


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## Doug Brott (Jul 12, 2006)

Vor said:


> <psst> RAID0.
> 
> RAID1, while being the lowest capacity, does have some advantage over RAID5 in reliability. With a complete mirror, if you lose a drive it just keeps going, while with RAID5 you're usually in a reduced performance mode while the controller has to calculate the missing data, and more reduced performance when the drive is replaced and parity has to be recalculated.


:lol: .. I should have reread my post .. you are most certainly correct .. RAID0  I've corrected my earlier post.

Only RAID0 or RAID5 configurations should be considered for the HR20 eSATA.


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## erp2863 (Aug 24, 2007)

I know it was predicted to work, but I just proved (at least to myself) that the HR20 does play nice with re-built RAID arrays. I swapped out one of the drives, re-built the array, re-connected to the HR20, and my recordings were still there.


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## 1948GG (Aug 4, 2007)

echo said:


> Yes, I will reformat the whole thing once I get the other two drives. I will post after a few weeks of operation and let everyone know if its working.


It's been just about 4 weeks since this last message from 'echo', who started this thread. Any chance on an 'update'?

Even though folks were generally grabbing at their wallets, the new Tenbox has way more doing the same, only quicker! But it's all about capacity, and now that the stream is about to turn into a firehose, just wondering if my budget for this thingy needs any kind of revision...!

TIA


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