Replacing hard drive in a Raid 5 array

[rsd]

Hi everyone,

I recently had a hard drive apparently die in my raid 5 array. It is a Maxtor DiamondMax Plus 9 250gb ATA/133 hd. Since it is an older model it may be hard for me to find the exact same one, so I was wondering if it mattered if I got a different model or brand instead? Or even a different capacity (assuming it was >= 250gb)?

Thanks so much,
Rob

 

[Vegito]

yes, you can even get a bigger size, it'll use the 250 out of 300 or whatever you get.

 

[rsd]

Originally posted by: Vegito
yes, you can even get a bigger size, it'll use the 250 out of 300 or whatever you get.

Thanks for the response vegito.

Let's say I get another 250gb from a different manufacturer--I know that the actualy number of bytes may be different than with my other drives, if it is slightly smaller will that be a major issue? Or should I just find a 300gb? Thanks so much

 

[bchivers]

I would make sure they are the same speed.

 

[rsd]

Originally posted by: bchivers
I would make sure they are the same speed.

I'll make sure to get a 7200 rpm one, but does the cache size matter? The others are 8mb, I wouldn't think it is a big deal though.

 

[Fullmetal Chocobo]

I have kinda ran into that problem, as I started my RAID 5 array with Hitachi 250gb SATA-150 hds. Well, they really don't make those much anymore, so I had to start getting SATA-300 Hitachi 250gb hds. Doesn't cause any problems, but I don't bother trying to run anything in SATA-300 mode (controller doesn't support it either I don't believe)... But I would stick with as close as you can get with the drives.

 

[RebateMonger]

Example of RAID 5 array where a slightly smaller replacement drive caused the array to fail to rebuild:

UseNet Post

 

[rsd]

Originally posted by: RebateMonger
Example of RAID 5 array where a slightly smaller replacement drive caused the array to fail to rebuild:

UseNet Post

Hmm very interesting. Now I'm leaning towards getting a 300gb just to be safe and letting that 50gb go to waste. It's hard to find the same model that died right now. Hmm.

 

[InlineFour]

mind telling us what raid controller you're using?

 

[rsd]

Originally posted by: InlineFour
mind telling us what raid controller you're using?

LSI MegaRaid i4 (ATA)

 

[InlineFour]

is this on a dedicated server pc, or on a everday pc?

 

[Fullmetal Chocobo]

Originally posted by: rsd

Originally posted by: RebateMonger
Example of RAID 5 array where a slightly smaller replacement drive caused the array to fail to rebuild:

UseNet Post

Hmm very interesting. Now I'm leaning towards getting a 300gb just to be safe and letting that 50gb go to waste. It's hard to find the same model that died right now. Hmm.

That depends upon your controller. Some controllers will let you use the extra space to make other arrays. So say you replace another 250 with a 300, and you have two 50gb sections, you could RAID 0 them. Just an example. I have a BroadCom 4852, and it does this and other things.

 

[rsd]

Originally posted by: InlineFour
is this on a dedicated server pc, or on a everday pc?

This is basically a dedicated server, I only use it to store files for my HTPC.

 

[rsd]

Originally posted by: Fullmetal Chocobo

Originally posted by: rsd

Originally posted by: RebateMonger
Example of RAID 5 array where a slightly smaller replacement drive caused the array to fail to rebuild:

UseNet Post

Hmm very interesting. Now I'm leaning towards getting a 300gb just to be safe and letting that 50gb go to waste. It's hard to find the same model that died right now. Hmm.

That depends upon your controller. Some controllers will let you use the extra space to make other arrays. So say you replace another 250 with a 300, and you have two 50gb sections, you could RAID 0 them. Just an example. I have a BroadCom 4852, and it does this and other things.

Hmm I'm not sure from reading the i4's manual, didn't notice it mentioning this. I wouldn't be surprised if it does not do this since it is a little old.

 

[RebateMonger]

I admit to popping a couple of 73GB Fujitsu SCSI drives into a RAID 5 array that'd previously been all Seagate 73GB drives. It worked fine. Maybe I got lucky (and Fujitsu drives are slightly bigger than Seagate drives), or else RAID cards intentionally leave a bit of unused space on drives when creating new RAID arrays, just in case a slightly smaller drive is injected into the array.

 

[redbeard1]

As previously touched on, you probably need to go with a bigger drive.

I ran across an issue with drives of the same brand and listed gig size, but the replacement drive had one less sector. The array controller could not rebuild to the "smaller" drive.

 

[sygyzy]

If you have a RAID5 of varying sizes, will the total size be limited by the smallest drive? That is, will the extra space in the other drives be wasted?

 

[redbeard1]

Originally posted by: sygyzy
If you have a RAID5 of varying sizes, will the total size be limited by the smallest drive? That is, will the extra space in the other drives be wasted?

The smallest drive will set the raids capacity. So a raid 5 with a 9 gig and two 18 gig drives, will set all of the drives to a virtual 9 gig each. The unused space is wasted and is not able to be utilized.

 

[sygyzy]

Thank you for that clear explanation.

 

[customcar]

Hi,

I have had the same problem with my RAID 5 setup. I have 3 Seagate 160GB, 7200rpm, 8mb 150SATA hard drives. Hard Drive on device 1 failed and I got the degraded status.

Well I could not find the same drive in SATA 150 spec so ended up with the SATA 300. I connected th new drive and booted up.

Now in my Intel Matrix Storage console I see the original 'Array 0' showing the 3 hard drives, with one saying 'missing hard drive'. But the new hard drive is located in 'non-RAID Hard Drives' area, amd I cannot work out why it did not get added to the original RAID 5. Or how to add it.

I looked at the Intel help section and it said that it should have been dected automatically and when I click the new drive it should be showing 'rebuilding x% completed'.

Any idea's?