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For those interested in mass storage for your HTPC I'd like to invite you to check out a new network attached media storage server product called Un-RAID .


This server has been designed specifically for digital media storage, with these key features:
  • You can mix and match up to 12 hard drives of any size and easily add or upgrade hard drives over time. That's a maximum capacity today of 5.5TB of protected storage using 500GB hard drives.
  • Like other RAID systems, uses a parity disk to provide fault tolerance against a single drive failure; but, what makes our system unique is that data is not striped across the disks.
  • Hard drives are mounted in removable trays.
  • All the operating system software resides in a USB flash drive.

Please use this thread to post any questions and comments.
 

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Interesting.. sounds like an offshoot of raid 4 without striping across the drives. Is parity calculated at each block on each drive? Looks like MAID array...
 

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Discussion Starter #4

Quote:
Originally Posted by shokunin /forum/post/0


Interesting.. sounds like an offshoot of raid 4 without striping across the drives. Is parity calculated at each block on each drive? Looks like MAID array...

Yes, you are exactly right: it's similar to RAID-4 without striping.
 

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Discussion Starter #5

Quote:
Originally Posted by Bal /forum/post/0


Is there the possibility as seeing the drives as a single drive versus seperate?

This is referred to as "concatenated volumes". We have explored this possibility and might offer it in a future software release. There are several reasons why we didn't implement this immediately:
  • In the event of a 2-disk failure, we don't want to take the chance of losing all your data. While theoretically this should be an extremely rare event, in practise, as some on this forum can attest, it does seem to happen.
  • This would increase configuration complexity. We want to keep things as simple as possible.
  • Today's HTPC front-ends, for example, Meedio, provide ways to specify any number of directories to "concatenate" into one data base. Hence in HTPC applications the fact there is a separate share for each disk is not restrictive in this respect.
 

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I really like the sound of this product. What is the throughput both Read and Write speed? I assume it is slower than RAID 5? I don't mind too much about the Write speed but am more concerned about Read speed as it may serve multiple streams/clients at once. I appreciate your response.
 

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These are my guesses from working with other raid systems...


Well, since each drive is its own volume, I would guess the performance is the same or worse than just a standalone disk. The disks are not spanned so there is no performance gain in reads by using this un-RAID. Writes would be slower than a single disk since parity would have to be calculated. I don't know if they mentioned how they perform parity (hardware vs. software), but since theyare using Linux, I'm guessing software raid.


Performance COULD be better if you were able to predict usage patterns and store files that would be accessed simultaneously on different disks. A modern single disk could handle multiples DVD requests, but it all depends on the demands of disk and performance. I didn't see any benchmarks on their website.


There's potential for energy savings and disk longevity by spinning down disks, but they using an intel Celeron proc still uses too much wattage for my liking (for something that is on 24/7)
 

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Discussion Starter #8

Quote:
Originally Posted by albrigsr /forum/post/0


I really like the sound of this product. What is the throughput both Read and Write speed? I assume it is slower than RAID 5? I don't mind too much about the Write speed but am more concerned about Read speed as it may serve multiple streams/clients at once. I appreciate your response.

Here is some performance information.


Sustained reads from a single disk share to a Windows XP machine via GigEthernet gets about 26 MB/sec (mega-byte = 1,000,000 bytes). The bottleneck here is the GigEthernet.


Sustained writes to a single shared disk get about 12 MB/sec. The bottleneck here is the un-raid disk subsystem.


We actually have not completed exhaustive peformance testing and tuning. We expect to be able to increase performance over time as our understanding of Windows/GigEthernet/Samba/Unraid interaction increases.


Bear in mind, the current numbers are far higher than needed to sustain video streams.
 

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Discussion Starter #9

Quote:
Originally Posted by shokunin /forum/post/0


These are my guesses from working with other raid systems...


Well, since each drive is its own volume, I would guess the performance is the same or worse than just a standalone disk. The disks are not spanned so there is no performance gain in reads by using this un-RAID. Writes would be slower than a single disk since parity would have to be calculated. I don't know if they mentioned how they perform parity (hardware vs. software), but since theyare using Linux, I'm guessing software raid.


Performance COULD be better if you were able to predict usage patterns and store files that would be accessed simultaneously on different disks. A modern single disk could handle multiples DVD requests, but it all depends on the demands of disk and performance. I didn't see any benchmarks on their website.


There's potential for energy savings and disk longevity by spinning down disks, but they using an intel Celeron proc still uses too much wattage for my liking (for something that is on 24/7)

Right on all counts



Some details... First, remember this system is designed for media data storage where ease of use, expansion, and low chance of complete data loss are very desireable features. Since it's a network attached device, the bottleneck is almost always going to be the network and/or the device from which the media data is being read from.


Regarding energy savings... We spin the disks down as much to save wear and tear on the disks as save energy (and reduce heat). We're working on a feature to cause the system to suspend after a period of inactivity, and then either wake up on it's own at a certain scheduled time or wake up via "wake-on-lan".
 

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Tom,


Thank you for the reply. I sent an email the other day. Please let me know if you didn't get it (I sent to the Lime Technology address) and I can send another one.


Sincerely,

Scott Albright
 

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It's impressive, but honestly pretty expensive. Considering the ability to (freely) use software RAID5, it's a hard sell.
 

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Quote:
Originally Posted by madpoet /forum/post/0


It's impressive, but honestly pretty expensive. Considering the ability to (freely) use software RAID5, it's a hard sell.

Yes software RAID is free, but you still need a system to run it on, and there are some significant disadvantages to RAID-5 for media storage applications.


Using retail prices for hard drives, by the time you've filled up the system, you are well under $1/GB. If you buy drives over time making use of sales and rebates, you can approach 50 cents/GB - ok, maybe 75 cents
This is extemely competitive with other RAID NAS devices on the market.


I realize most people on this forum "build their own" (as do I). My motivation for starting this thread is not to drum up sales necessarily, but to have our approach critiqued by people I know are knowledgeable.
 

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I think what madpoet is getting at is the cost (without drives) is the price is rather high for your software, considering the cost of the hardware. I was pretty interested until I saw the pricetag. (Coming from a guy who has an 8 drive + 3ware RAID-5 array).
 

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I had to laugh when I saw the picture.... It looks exactly like my media server. I have the same Coolermaster Stacker case with 8 of the Cremax hot-swap drive bays installed. It looks pretty slick.... of course you already knew that.


Eric
 

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Discussion Starter #15

Quote:
Originally Posted by stanger89 /forum/post/0


I think what madpoet is getting at is the cost (without drives) is the price is rather high for your software, considering the cost of the hardware. I was pretty interested until I saw the pricetag. (Coming from a guy who has an 8 drive + 3ware RAID-5 array).

Fair enough. Actually, a big part of the cost is assembly and a shipping container. We don't have the volume (yet
) to have them mass assembled.


Out of curiosity, if you were to build your current array using a 3ware card, mobile racks for the drives, and a high quality case and power supply, what would it cost you per GB of storage (and no fair using an old motherboard you have laying around)?
 

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Discussion Starter #16

Quote:
Originally Posted by FrothyDog /forum/post/0


I had to laugh when I saw the picture.... It looks exactly like my media server. I have the same Coolermaster Stacker case with 8 of the Cremax hot-swap drive bays installed. It looks pretty slick.... of course you already knew that.


Eric

Isn't this the best case you have ever owned? It's so easy to work on and they include a lot of nice touches like the wheels and connector for hooking up two power supplies.
 

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Quote:
Originally Posted by limetech /forum/post/0


Fair enough. Actually, a big part of the cost is assembly and a shipping container. We don't have the volume (yet
) to have them mass assembled.

Granted.

Quote:
Out of curiosity, if you were to build your current array using a 3ware card, mobile racks for the drives, and a high quality case and power supply, what would it cost you per GB of storage (and no fair using an old motherboard you have laying around)?

I'll answer this without discussing drive prices because you sell your system without drives, so we'll compare apples to apples.


I've got a 3ware 7506-8 RAID card, I can build (as near as I can tell without knowing your exact part numbers) your hardware from newegg + that RAID card for $1060.42. Now remember than includes a RAID card that's $395 (the 12-port version is about $200 more so a whole 3ware 12-port setup would be about $1300). So that means I can buy your hardware for $665.42, basically half what you're charging. That would be the PATA config, for the SATA config (3ware 9500s) in the 12 port, that would be just over $1350.


Now take it as constructive criticism, because again, it is an interesting setup, especially with the parallels to the Kaleidescape system (which is also a RAID-4 or similar setup). I think if you just sold the flash drive with your software (and an appropriate list of supported configurations) for something in the neighborhood of $50-100 you'd get a lot of bites from those like us.


-edit

FWIW, I already had a donor PC, and built my array when 250GB drives were the sweetspot price wise (about 9 months ago), my array (3ware+drives) cost me ~$1300, but 250GB drives were running 125-150 at the time.


-edit 2


Also my array is nearly full so I'm keeping an eye out for attractive storage solutions.
 

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Discussion Starter #18

Quote:
...So that means I can buy your hardware for $665.42, basically half what you're charging...

Hmm, our h/w costs more than that & we use volume pricing...

Quote:
Now take it as constructive criticism, because again, it is an interesting setup, especially with the parallels to the Kaleidescape system (which is also a RAID-4 or similar setup). I think if you just sold the flash drive with your software (and an appropriate list of supported configurations) for something in the neighborhood of $50-100 you'd get a lot of bites from those like us.

Thank you. This is the kind of feedback I'm looking for. We can definately offer the software on a Flash drive, and not only that, provide detailed assembly instructions on our website for those who what to "roll their own".

Quote:
-edit

FWIW, I already had a donor PC, and built my array when 250GB drives were the sweetspot price wise (about 9 months ago), my array (3ware+drives) cost me ~$1300, but 250GB drives were running 125-150 at the time.


-edit 2


Also my array is nearly full so I'm keeping an eye out for attractive storage solutions.

The 320GB PATA drives are currently the "sweet spot". One think nice about our system is that you can upgrade drives in place. So in a few months you could replace those 250's with 500's.
 

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I would GLADLY buy and try your software on a flash card in that range. I've already done it once with a competitor product for $150 and it worked very nicely, but had more limitations than yours seemed to. I would also urge you to consider it.
 

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Quote:
Originally Posted by limetech /forum/post/0


Hmm, our h/w costs more than that & we use volume pricing...

Kind of like local PC shops, they usually have a really hard time competing with online (newegg) as well.

Quote:
Thank you. This is the kind of feedback I'm looking for. We can definately offer the software on a Flash drive, and not only that, provide detailed assembly instructions on our website for those who what to "roll their own".

There will always be a market for the ready-to-go stuff, but I'd guess that you'd get a lot better (ie more sales) response from AVS-types with a "roll your own" option.


Quote:
The 320GB PATA drives are currently the "sweet spot". One think nice about our system is that you can upgrade drives in place. So in a few months you could replace those 250's with 500's.

I've been back and forth on that, and come to the conclusion that (no offense) that "benefit" isn't one. I mean, sure you can upgrade to larger drives, but then what do you do with the old ones? Sell them for pennies on the dollar? I figure, you'll be upgrading due to increased storage need, so it's more logical to keep what you have, and just add more
 
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