CPBackup on a server with Raid 1+0?

[JohnM115]

We are looking at getting a new server, and we are thinking about getting 4 drives in a Raid 1+0 array (mirrored and striped).

However, we cannot get more than 4 drives, so we can't get a 5th drive as an "onsite" backup. (We of course will also have an offsite backup, but we need an "onsite" backup to create the files to later move offsite, and for easy access to restore accounts or files from a previous time.)

Would it be a problem if we created our /backup partition on the same 4-drive Raid 1+0 array as the rest of the system? Backups would be weekly, but I'm not sure if backing up from a RAID 1+0 array to itself would cause high load or iowait. We would be using cpbackup for the backup.

Also, if we have to hard reboot the server, could that cause array corruption? I've read conflicting posts about that. I know a hard reboot can generally cause problems with or without RAID, but does it cause more problems with RAID (or increase the chances of problems)? Might I be stuck one day waiting for the entire array to rebuild?

[gvard]

Hello,

I don't think there is a problem using /backup partition under your RAID configuration and I don't think there will be more IO, since the backup is first taken on /home/cpbackuptmp and then the tar file is moved to its final destination.

[godalmargo]

Hi JohnM115,

Although it's possible to use your raid array to backup, it's not advisable. You will create a higher load during backup, and much more stress in your main disk drives.

Kind Regards,

Hugo

[Indianets]

Hello,

It would be an stress to the disk array, specially if you use compression and the server is a bit busy.

You can use a shell script to 'pkgacct' and then 'rsync to offsite' one by one for all accounts on weekly basis. You can avoid compression to get better results (will use more bandwidth to the offsite server though). Also, you can leave the homedir while doing pkgacct and sync them later at once to use the rsync's only required data transfer.

- Vijay