[CentOS] Virtualization as cheap redundancy option?

[Emmanuel Noobadmin]

> You cannot do rsync on a continuous basis, so I think you have your
> answer there.  Even running it once an hour isn't going to work, as
> the machine will be inconsistent (very bad disk corruption).  It

That's what I figured too, otherwise it should/would had been an easy solution.

> sounds like you need to get some new servers anyway, so DRBD is
> probably the way you need to go.  Either that or a dedicated SAN or
> SAN-like device.

DRBD as I understand it, is effectively RAID 1 over network. Which was
the 2x cost and budget problem I had. Would the 2-machine Lustre
cluster I'm considering to implement work as adequate as a  SAN
device?

> The creeping CPU problem happens slowly over the course of a week or
> so, so if you're seeing acute freeze-ups, then that's probably not it.
>  However, if all machines have been running for a while, try to
> suspend/resume all of them, then see if the problem goes away.

That is pretty much what we see. Sometimes we leave the machine on
through several days if there was no changes to what we are doing on
it and sometimes the VM freezes after a few days. Had appeared random
because anyone of us could have restarted the VM during the week so
those lock up probably happened when none of us did.

However, the CentOS machine itself is still responding when we vnc/ssh
in so we would have to kill and restart the VM service before we can
use the VM again. Sometimes that doesn't work and we have to reboot
the machine.