Backup 3 Drives to 1. Possible Raid?
 

Hi,

Does anyone know if its possible to backup 3 drives to 1, I currently have 3 seperate drives in my server (there old ones that total to about 300 gig) and I want to back them all up to one drive just incase. If i bought one drive would it be easy enough to set it up as a backup and also can raid do this and are there any major performance issues?

Thanks,
Julian

Welcome to LQ! :)
I don't think what you want to do is something that can be easily achieved with RAID.

As you've only got 300GB of data you should be fine with one large drive and then one of the many supported linux backup programs.

Hi Ju,

Theoretically speaking, the new hd will have a better performance than the 3 old ones. Hence, which method you intend to use:-
1) Use the old hd's has primary (raided) and new asa backup
2) Use the new hd has the primary and the old as backup

Performance won't change in the old ones.

However, I would have setup the new hd as my primary hd to increase daily performance on the workstation. Then raid the 3 old ones for dail, weekly , monthly backup. Which could be done over night.

Regards,

Remember, RAID is not a backup solution. It's failover type protection in case hardware fails and gives you time to replace. But it's never ever ever ever a backup solution. Just thought I'd throw that out there for anyone who wasn't aware.

Thanks for the help guys,

So if i set up a new drive as the primary and put all the data into the new one then just use a backup program to backup the relevant parts to the old drives?

We did some theory about RAID in college which is why i thought it would be easier to just get the one drive to mimic all the others.

Just got a couple of questions,
1. is it possible to virtually join the 3 old drives into one?
2. if i copy the entire linux filesystem across will it work without needing a reinstall? (Running Ubuntu 7.10)

Thanks

For (1), look into LVM (logical volume management)

Regarding (2), you can transfer your install to a new drive, but there are a couple of potential issues, which can be easily patched up:

1. If you copy your installation to the new HD file by file (using rsync -a), you will need to re-install grub to the MBR of the new drive. I usually do this by booting from my rescue disk, chroot to the installation on the HD, and running grub-install.
2. The new drive may be detected by the bios differently from the old one, and end up with a different device name ( hda becomes hdb or sda, for example). This change will need to be reflected in your grub menu.lst and possibly device.map, as well as fstab. You can do this in rescue mode as well.
3. If you switch to a new drive technology, say from ata to sata, the driver for the controller chip, which is loaded at boot time, may be different. This is fixed by making a new initrd in /boot, using mkinitrd. Again, this can be done in rescue mode.

Ok guys, I'll start looking into LVM (only ever used it on the fedora default install :o)

Thanks for the help