RAID Migration

[Mike Sylvan]

I am about to do a RAID 0 to RAID 5 migration on a Proliant ML570 with the 5300 array. In the event of an unexpected shutdown during the migration process, what effect it will have on the migration? Once the server is brought back online will it continue the migration process?

[Joshua Scott · Accepted solution]

I don't have experience with this specific setup, but I would expect that a power outage during a migration would cause total data loss.

This is why it's essential to do a full backup of your data before performing migrations.

[Mike Sylvan]

Thanks for your response. The server will be running backup jobs during migration, will the server encounter performance issues? Are there any other "hidden" blackspots that I should be aware of?

[DGH_2]

Hi,
i preffer that you do a full backup before doing the migration and not in the same time.
not only the loss of performance that you should take in consideration but also a pwer failure will cause loss of data and backup.

Dory

[Joshua Scott]

I agree with dory. a raid migration is a dangerous thing to play around with. if power were to fail, you could lose both your backup and all data on the array.

[Mike Sylvan]

I see your point guys. Just one more thing. This server is our main backup server and we cannot stop the backup due to the time it takes and the amount of data it backs up. Before we start the migration we will have a full backup first, start the migration, then restart the backups(It takes 4 days to complete). Is this a wise thing to do?

[DGH_2]

Mike,
what you need is a full backup before the migration to cover yourself. and if not you can take the risk.
after the migration why you need a backup directly. you can schedule a backup as it was before.
4 days is better than lose everything.
Dory

[John Marinov]

I expect that it will continue the migration process. A 5300 is a high end, battery-backed controller, and the migration is done by the controller, not the OS. During array rebuilds (ie replacing failed drives and getting rebuilds done) I have rebooted servers without any problems at all.

Yes, you should do a backup, but you need to be doing backups anyway.

How many disks are in this raid 0 set? Two? Or more? You need a minimum of three disks for a raid5 volume.

If you have any spare hardware (like disks), you can check this by running up a system with a 0+1 volume, and test the conversion. If you had enough disks, you could remove one of the mirrors, replacing the disks with spares and that would give you an instant backup.