Adding a new HDD to a Raid 5 setup

[DM101]

Dear All

I am currently running a 3*400GB HDD Raid 5 set up and I am looking to add a new 1TB HDD to my setup. The system will allow up to 5 HDD's so there should be no problem adding the new HDD, however, I was wondering is it possible to add a larger drive to a RAID 5 set up.

My eventual aim is to add the 1TB and then slowly convert the 300GB drives to 1TB in the future.

If you have any advice it would be greatly appreciated.

Thanks

David

[ExtremePC]

Originally Posted by DM101

Dear All

I am currently running a 3*400GB HDD Raid 5 set up and I am looking to add a new 1TB HDD to my setup. The system will allow up to 5 HDD's so there should be no problem adding the new HDD, however, I was wondering is it possible to add a larger drive to a RAID 5 set up.

My eventual aim is to add the 1TB and then slowly convert the 300GB drives to 1TB in the future.

If you have any advice it would be greatly appreciated.

Thanks

David

To increase the capacity of the RAID volume, no. You can add the 1tb drive as though there was a failure by pulling one of the other drives out but it will rebuild to only the same "size" as the drive you're pulling out.

[DM101]

Thanks for the feedback.

Would I be able to add the drive to the machine as an extra drive outside of the raid setup.

i.e 3*400GB HDD in raid 5 setup
1 * 1TB HDD as a seperate drive

Thanks

David

[ExtremePC]

Originally Posted by DM101

Thanks for the feedback.

Would I be able to add the drive to the machine as an extra drive outside of the raid setup.

i.e 3*400GB HDD in raid 5 setup
1 * 1TB HDD as a seperate drive

Thanks

David

Of course you could.

[charlesc3]

Originally Posted by DM101

I am currently running a 3*400GB HDD Raid 5 set up ...

David, as a matter of interest, how are you implementing your RAID 5 system?
Is it through the motherboard BIOS and the OS, through a dedicated hardware card, through a software solution?

Having had a few hard drive failures over the years, and having spent quite some time recovering data with various programs, I've always been surprised how many posts there were on those data recovery forums with people that had problems with disks in RAID configurations. Quite a few times it seemed the RAID function (whether through hardware or software problems) broke, and the disks were no longer part of a working set.
And data recovery in that situation is so much harder than with a simple disk.

There are a few links here that discuss some typical problems, or situations that happen.
http://www.dtidata.com/raid_5_data_recovery.htm
http://forums.nvidia.com/index.php?showtopic=47666

I mention it because some implement a RAID solution expecting it to absolutely rock solid, and don't expect problems can happen with it. Unfortunately that doesn't always seem to be the case.

[DM101]

Excellent

Thanks

David

[DM101]

charlesc3

I purchased the machine pre built, however, I believe the RAID 5 setup is via the motherboard and BIOS rather than a seperate card.

I will have a look at the sites that you have listed.

For the most important files on my machine (photos and music) I keep an additional copy of these on an external drive so that I lower my chances of losing them in case of a failure.

David

[buccaneerbob]

Some hardware raid controllers allow you to add drives to an existing raid 5 array. It's called online capacity expansion and basically allows you to hot-plug a drive without taking the array off-line. You can then extend the partiton with diskpart and your extra storage is available. You have to spend the $ on a good raid controller though.

[itr2401]

The other aspect to consider is the S3 state of the machine (if you have a raid card in a box that will be put into a sleep state).

After some careful investigations, my 3ware 9550 controller does not like waking from an S3 state - the OS recovers fine, just at first disk access the OS hangs requiring a hard reboot. Looks like I will be moving those cards to my NAS. I suspect this could be a driver issue, however stock MS & vendor drivers with latest card firmware's fail to resolve the issue when in a box resuming from an S3 state.

Using onboard SATA raid 5 (Intel S5000XVN with added module) there is no problem with resuming from an S3 state.

With the 3ware card I can grow an existing raid configuration by adding in a drive and expanding the array, the intel doesnt allow me to do that.

FYI - the above was on XP / Vista, not running MCE but systems I use for my work.