[TriLUG] Hard drive recovery

[Rick DeNatale]

On 8/29/05, Owen Berry <oberry at trilug.org> wrote:
> 
> I would classify it as delayed remote raid. :-) Not a backup, but useful.
> 
> Owen


Keep in mind that RAID IS NOT BACKUP either. In fact in some ways raid alone 
is worse than an occasional snapshot copy to another device.

Raid gives you protection against hardware failures. But hardware failures 
aren't the only cause of data loss. Human error (hereafter refered to as an 
oops, not to be confused with kernel oopsen) is another. What if you write 
over or delete your important data? Raid will give you a redundant copy of 
the corrupted/deleted data. An occasional snapshot backup MIGHT help if you 
did the snapshot recently and before the oops.

A good backup strategy will not only let you get back to before a hardware 
failure, but also before an oops.

As advised by the session which Jason and Jeremy did last year on backups I 
do rsync based incremental backups on my workstation/server to a separate 
physical hard drive. This gives me redundant copies of the current state of 
my data, as well as historical backups. If one of my main drives fails I can 
recover recent state (no longer than 4 hours ago) from the backup. And if I 
oops I can go back four hours, yesterday, last week, two months ago etc.

I guess I can live with the slight possibility that an oops coincides with a 
failure of my backup hard drive.