Need some opinions on a raid5

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Mr34727

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I am looking to upgrade the storage in my computer right now. I currently have a seagate 5900rpm 1.5tb drive I got about a year ago when it was an amazing deal to get one at $100. Now, I need more space. My concern, however, is that as my data builds up, losing it would suck exponentially more.

I am thinking of going with a raid 5 array, probably with 3x1.5tb or 3x2tb. Please correct me if I am wrong, but this would give me 3-4tb usable space, and allowance for one drive failure?

Now, looking around, I want to buy a WD drive, just because they have RMAd around 6 drives for me hassle free this year. I am looking at the Caviar Black, and the AV-GP drives, wondering which would be better for my usage.

The computer stays on 24/7, but the boot drive is a raptor, so currently my storage drive jsut spins down. My concern is putting an AV-GP drive into a raid 5 array. Is this a bad idea? Should I spring the extra cash and go for the black drives? Thanks!

ps- onboard raid controller, Gigabyte 790xt board
 
Mr34727 said:
I am thinking of going with a raid 5 array, probably with 3x1.5tb or 3x2tb. Please correct me if I am wrong, but this would give me 3-4tb usable space, and allowance for one drive failure?
Click to expand...

Correct.

Mr34727 said:
Now, looking around, I want to buy a WD drive, just because they have RMAd around 6 drives for me hassle free this year. I am looking at the Caviar Black, and the AV-GP drives, wondering which would be better for my usage.

The computer stays on 24/7, but the boot drive is a raptor, so currently my storage drive jsut spins down. My concern is putting an AV-GP drive into a raid 5 array. Is this a bad idea? Should I spring the extra cash and go for the black drives? Thanks!

ps- onboard raid controller, Gigabyte 790xt board
Click to expand...

Several problems with your plan:
- The onboard RAID controller of most mobos have slow RAID 5 performance. Roughly 20MB/s to 40MB/s write speed. Though the newer ICH10R can hit 70MB/s write apparently.
- It uses your CPU to handle the parity calculations. As such you might see anywhere from 10% to 50% CPU constant CPU usage at all times depending on the size of the RAID array.
- Most WD consumer drives might not work too well with many RAID controllers due to their lack of TLER. As such, the RAID array might kick a drive or two occasionally. Your best bet for a RAID drive are Samsung and Hitachi drives. Use WD if you're planning on using Linux software RAID.
 
Why are you looking at the AV-GPs? Are you continuously storing and replaying video?
These drives are designed for DVRs/security camera systems and lack error correction more or less required by a computer. While they will work, they are extremely not ideal for data storage.
 
Thanks for the input guys. I was mainly looking to WD because of the great service I have recived from them in the past. If you are saying I should go with seagate, etc, thats cool too. Any drives you would recommend?

So you are saying I should go with a dedicated pci/pcie raid controller? Anything decently priced for a home user? I have seen used raid controllers on H for $500+, and I am really not looking to spend that much.

Usage- The video is encoded using handbrake/anydvd/Phenom [email protected]. I really dont care too much about write speed, because it will just be storing media.

I was looking at the AVGP drive because they advertised they could be used in 24/7 atmospheres, which I am doing- computer stays on all the time, only rebooting for updates. It does not, however, have a tuner or anything that would require harddrive writes when I am not using it, I just dont shut it down.


Thanks for the help guys! Keep it coming!
 
Danny Bui said:
. Your best bet for a RAID drive are Samsung and Hitachi drives.
Click to expand...

Does that include the Samsung EcoGreen drives?

I want to build a RAID5 array too and already had 3 WD20EARS bought and then read the issues with them. I was debating the EADS models but no guarantees I will be able to enable TLER etc.
 
I was staying away from green drives because I read they spin down to save power, which wouldnt be good in a raid array, as they would need to spin up and down alot, putting more wear on the drive. This was with WD drives though, so im not sure about the ecogreen drives.
 
I would go with Hitatchi (my Raid 1 setup) or Seagate, myself. WD should be fine as well, I'm not aware if any commands they would not have that the others would.

For streaming large writes ie video surveillance or video rendering, consider Raid 3. Slightly more efficient than Raid 5 in the big writes, but not enough to really kill yourself over to find a card that does it.

For overhead-efficiency, I would go for a 5 disk (4+1 in EMC speak) Raid 5 if your controller will support that. 20% overhead isn't so bad. The main argument of not using fewer drives is the amount spent on the overhead, and more than 5 you get into longer rebuild times.

This is most likely overkill, but Adaptec is known for making good Raid controllers:
$200, Adaptec 5085 RAID 8CH 512MB 2249100-R
http://cgi.ebay.com/Adaptec-3405-4-..._EN_Networking_Components&hash=item2a0860e396

Good Luck,
-Steven
 
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Hey thanks for the input Steven, I am somewhat unclear as to the efficiency of a 5 disk array. Do you mean cost wise?
 
Mr34727 said:
Hey thanks for the input Steven, I am somewhat unclear as to the efficiency of a 5 disk array. Do you mean cost wise?
Click to expand...

I think Steven talk about the N-1 usage space in raid5 - where N is the number of HDD in raid

example you have 5 drives ==> usage-able space = 4x drives (20% overhead)
or 10 drives ==> usage-able space = 9x drives (10% overhead)
so on - Correct me if i'm wrong Steven

__
 
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