SCSI drives recommendations

[Bob Edwards]

Richard Cottrill wrote:
> In terms of securing your client's data: I'd think that regular backups are
> the way to go. RAIDs are not a replacement for off-line backups (although
> the off-line backup could itself be on a RAID). I'm not too clear about the
> best backup strategy for databases. I'm pretty sure there isn't a good way
> to back up a live database though - for mine this implies some kind of
> redundancy to make the DB available 24x7. Any recommendations on this topic
> are welcome because this isn't something I've got to do - although I soon
> might.
> 
> Richard

This is a good point. RAID has three main pros:
 - protection against a single disk drive failure (RAID 1 and 5)
 - increased disk capacity (RAID 0 and 5)
 - increased disk system performance (RAID 0)

As for protecting data integrity, you need a backup system. RAID is not
a backup system (but could be used in one - each of our backup servers
uses RAID).

RAID won't protect you from:
 - a single user failure ('rm -f *' - woops!)
 - a single disaster (fire, flood, theft)
 - a single system compromise
 - a single kernel failure

A journaling file system (even one on RAID) might help protect you against the
first one of these, though.

Cheers,

Bob Edwards