Web Hosting Talk : Web Hosting Main Forums : Dedicated Server : upgrading storage on hardware RAID 10 possible?

[SoftDux]

Hi all,

Can anyone please tell me, from experience, if it's possible to upgrade the hard drives in a RAID 10 system from 250GB HDD's to 500GB / 750GB HDD's, while the server is running? The server runs CentOS 5.5 x64.

Our hardware vendors simply always say no, so we never actually tried doing this, and when a client needed an upgrade like this we had to build a new server with the same spec and larger hard drives and then migrate the data across, which can sometimes take a few days to complete (due to DNS & MAC address caches).

So, I'm wondering, is it possible (and safe) to upgrade the existing drives to larger drives in a running server?


I know we're done this with Linux's software RAID many times with great success. But I don't want to take a risk if it's not possible. The amount of effort and upfront costs for a new server makes hardware RAID far more expensive than it's reliability, which Linux's software RAID offers equally so I'm beginning to think we should just move all the servers to software RAID in the future as well.

[rghf]

We've done it a few times where over the course of a week you replace a disk, let the RAID rebuild and repeat till all disks are done. Tweak the hardware RAID card as needed by adding a new volume or extending if it allows it. Then do it on the OS level (or add a new partition etc). Its not a quick process but its definitly doable

rus

[SoftDux]

Thanx Rus,

So as matter of interest, did you have to reboot the machine to make the changes, or not? This particular machine is used as shared storage for a few XEN VM's, and I would like to keep it running during the upgrade. The machine specs are also a bit more unique than the others so if I have to buy another one of these servers then it's probably going to be a "dead weight" for a long time.

[rghf]

For replacing the disks no. For tweaking the RAID we did just to be safe. Could you do it all online? What RAID card is it?

[johncor]

It depends on your hardware RAID controller. I'm assuming it supports hot-swap so you should be fine to replace with a larger capacity disk. When you've replaced all the disks you will want to make sure your controller recognises the increased capacity.