Sign in with
Sign up | Sign in
Your question

New RAID Setup

Last response: in Storage
Share
March 20, 2012 6:23:24 PM

I am trying to figure out what sort of RAID setup I want for my new desktop builds. I would like to do two separate builds, one for Linux and one for Windows, so I can run them both simultaneously and use a KVM for maximum productivity. Have potentially considered virtualization as well with Linux as the underlying host, but maybe two machines would be better in terms of speed, stability, and productivity. Would also like to use the Windows machine for 2d surround gaming on three monitors, and not sure if this is supported in Virtual box.

Anyway, trying to decide on a good RAID setup for my boxes. I used to think that fakeraid was actually true hardware raid, I won't make that mistake again. So should I do software RAID then? How does that work? Is that done by the OS? If not, where is it done?

My concerns are read speed and data retention. Capacity is nice, but somewhat secondary. Considering these priorities, my first inclination is to do a three drive RAID 1, or potentially even a four drive RAID 1. Would it be possible to start with a two drive RAID 1, then later buy a third drive, and then move up to a four drive as needed?

I'm assuming since these are just mirrored, I should be able to pull any one of the drives, throw it in another machine and be able to read all my data just fine.

I've had a nightmare situation before where a fakeraid suddenly didn't detect the entire raid 1 config in the bios!! I need to avoid this situation at all costs. I am assuming this is a fakeraid issue and shouldn't be a problem with software RAID.

Thanks!!

More about : raid setup

March 20, 2012 7:51:53 PM

I would recommend using a hardware RAID solution as otherwise you will rely on the o/s to do the RAID and that can slow things done. you can buy motherboards which do RAID or you can get a separate RAID card but buying a mobo that supports RAID will be cheaper.

RAID1 is mirror as you mentioned. I don't see why you would want to mirror more than 2 drives. The point of RAID1 is that if one disk fails, you simply break the mirror and no data is lost.

If you want to be able to add disk and gain the extra space then RAID5 is the way to go. you need a minimum of 3 disks for RAID5 and i disk is used for parity so you only get usable space from 2. Say you buy 3 x 1TB disks and use RAID5 then you only get 2TB to use, which comes out at approx 1.8TB once formatted

Personally I would just use 2 disk RAID1 and just use big disks (1TB). That space will last you a long time. If you want more space then I suggest investigating NAS to store your data and just put games on your actual PC :-)
m
0
l
March 20, 2012 8:23:15 PM

I guess my issues are as follows:

1. RAID 5 is much slower than RAID 1.
2. Three disk RAID 1 can tolerate two separate drive failures, which I would like to have the option of at some point.
3. What mobs have TRUE hardware raid cards vs fakeraid?

Thanks!!
m
0
l
Related resources
March 20, 2012 9:51:24 PM

I use a four 500gb drive raid 10 on my systems. Increase read speed, data protection, minimal write speed degradation. Most modern Intel motherboards with SATA support hardware raid, its a part of the chipset.
Never heard of fake raid in 30 years of conputer work. Unless you are refering to software raid.
m
0
l
March 20, 2012 10:07:10 PM

My guess is that you are probably running fakeraid at the moment. Fakeraid is sort of a combination of hardware and software raid, from what I can tell.

http://serverfault.com/questions/9244/how-do-i-differen...

Sounds like you're doing fine with that chipset though. What chipset are you using for RAID? Have you tried rebuilding the array yet? Can you hot swap? Are you able to pull two of the drives that are striped and recover all your data on another machine? (Please don't try anything and lose data because of this post though!!!)

Thanks!!
m
0
l
March 21, 2012 1:19:42 PM

Totally up to you whether you chose RAID5 or RAID10 but the general consensus is that RAID5 is better at reading and RAID10 is better at writing

http://www.kendalvandyke.com/2009/02/disk-performance-h...

Personally I would prefer a quicker read time as this will speed up game loading times. I perform more read operations than write ...

Also you need to check your mobo supports RAID10, not all do. Start looking at Gigabyte, Asus mobos ... Newgg allows you to filter search results depending on RAID capability
m
0
l
March 21, 2012 6:00:35 PM

I would rather have three disk RAID 1 than RAID 10 though, because I want to be able to sustain *any* two drive failures. RAID 10 can totally fail if both failed drives are in the same mirrored pair.
m
0
l
March 22, 2012 2:07:37 PM

Sounds like RAID1 is the way to go then. Just curious .. why are you so worried about two drives failing at the same time ?
m
0
l
a b G Storage
March 22, 2012 10:33:30 PM

foulowl said:
... fakeraid was actually true hardware raid, I won't make that mistake again. So should I do software RAID then? How does that work? Is that done by the OS? If not, where is it done?


Linux term fakeRAID is software RAID :-) host CPU controls it

foulowl said:
... three drive RAID 1, or potentially even a four drive RAID 1. Would it be possible to start with a two drive RAID 1, then later buy a third drive, and then move up to a four drive as needed?


Where can you find three drive hardware mirror? I want to know, i need one of this raid. That would be fantastic for database server swap drive daily without encounter RAID critical condition, because there is a second drive as mirror - similar to RAID6, two drives fail data still OK

foulowl said:
I'm assuming since these are just mirrored, I should be able to pull any one of the drives, throw it in another machine and be able to read all my data just fine.


It should.

foulowl said:
I've had a nightmare situation before where a fakeraid suddenly didn't detect the entire raid 1 config in the bios!! I need to avoid this situation at all costs. I am assuming this is a fakeraid issue and shouldn't be a problem with software RAID.


There is no different between software RAID and fakeRAID :-)

Anyone have input in three drive mirror RAID? TIA
m
0
l
March 27, 2012 12:00:39 AM

I want to be able to sustain two drive failures because guess what...with two drive RAID 1 when RMAing the failed drive, the other will fail haha. I want to protect against this failure condition. I know it is unlikely, but still. Also, better read speeds?

Anyone find out anything yet about hardware that supports three drive RAID 1? It would be cool to see some benchmarks too.
m
0
l
a c 302 G Storage
March 27, 2012 4:05:51 PM

foulowl said:
I want to be able to sustain two drive failures because guess what...with two drive RAID 1 when RMAing the failed drive, the other will fail haha. I want to protect against this failure condition. I know it is unlikely, but still. Also, better read speeds?

Anyone find out anything yet about hardware that supports three drive RAID 1? It would be cool to see some benchmarks too.

If you are going to go that far, have a spare drive on hand. If one drive fails, you replace it and start the rebuild immediately. Some separate hardware controllers even support "hot spare," an unused drive that's rebuilt into the degraded set as soon as one drive fails.

You can also try RAID 6. It's like 5 but with two parity drives, so it can survive the loss of two spindles. Two warnings about RAID 5/6. First, the writes will be slow unless you have a controller that does the parity calculations in hardware. Motherboard chipsets don't do this. RAID 10 (or 1+0) involves striping and mirroring but not parity. The others require parity calculation. Cheaper solutions that offload these calculations to the CPU are slower, even with a fast CPU, because the data has to be moved more times. Second, RAID 5/6 tends to be slower than a single drive until you get up to at least three drives plus the one or two extra for parity.

Finally, the obligatory unasked-for advice. No RAID level is a substitute for backups. They can protect your files against one or two spindle failures, but not malware, rain, or the recent example of a three-year-old banging the machine on the wall.
m
0
l
!