[sclug] Mirror disks across machines like distributed RAID?

[John Stumbles]

ISTR some discussion here on something like this but can't find the thread.

While I was away at xmas my home mail+file server went down. I assumed 
the router had just got its knickers in a twist (as it's wont to do) but 
found that the little boot IDE HDD on the server itself had gone very 
bad, and it also looked like the mobo on the machine (a pre-loved box 
from one of the folks here) had developed some funniness (looked OK but 
an OK CD on an OK CDROM drive would look bad when you tried to read part 
way through it).

Anyway it got me thinking that a RAID-1 filesystem's all very well for 
preserving the data on a disk but it doesn't help if/when the host 
system goes bad, and I could really do with having two boxes capable of 
running the same services (NFS, SAMBA, imapd, httpd etc) each with one 
of the HDDs that would be in the fileserver, and to replicate data from 
one HDD to the other.

One could hand-roll this with master and slave HDDs, using rsync to keep 
the slave more-or-less up to date with the master, but is there anything 
that does this for you? What would be really kewl is to have the two 
linked drives act as one virtual drive (is that what a SAN is?) but 
maybe that's a tall order.

Thoughts?

-- 
John Stumbles                                       http://yaph.org.uk
:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-: