[plug] Raid-5 recovery

[Craig Ringer]

Jon Miller wrote:
> I agree Craig, as I have to do a 4 x 146GB backup, since the initial drives are SCSI U320, what I've done is the following:
> 1) setup a RAID5 DAS with 4 x WD200GB ATA100 drives with a hot-spare drive in  Promise SC4000 DAS  and I have an image of the SCSI copied to the IDE/SCSI RAID5 system.

Those SCSI-attached ATA RAID enclosures are very cool gear. A little 
pricey for me so far - I'm doing OK with internal storage - but I expect 
to need one sooner or later.

> 2) setup the backup of only data to a Ultrium Backup system

Same; DDS4 in my case, as our regularly altered data fits (just) on DDS4.

> 3) once a month backup of the OS

Yeah. I drop /var, /, and /usr to tapes (one tape each) and take them 
off site. Again, monthly. I drop all of /etc and select bits of /var 
into the nightly tapes too, so I can more easily bring the server 
up-to-date after a failure.

I should be getting 4 medium-sized SATA disks soon so I can use those 
for the server images instead (2 pairs of identical mirrored copies - 
one on site, one off), but that's mostly a matter of speed.

> This way I get an entire server copied to an online system although the drives are ATA in a RAID5 configuration the connection to the server is SCSI.  Then I have a daily backup of the data only partition on tape.  
> 
> It's getting difficult to get a system that is reliable is the main problem. 

... though partially because the market is driving manufacturers toward 
"cheap over all else."

Craig Ringer