On Fri, Dec 24, 2010 at 11:00:48AM +0100, Webcharge wrote:
> Must be the holiday season *sigh*.... my OpenBSD server is suddenly
> giving the occassional read-timeout on the /var slice of the main
> harddisk:
> There is a second harddisk installed, with OpenBSD formatted slices,
> but of different proportions. This (larger) disk is unused, so data
> / layout may be wiped,
> so it seems like smart idea to copy the data at least (I do have
> offsite backups of essential data but not a spare system in the rack
> at this very moment)
>
> Can I "just copy /var (wd0g) to /var2 (wd1i) and remount" or should
> I proceed otherwise or would copy/remounting /var simply not work on
> a live system?
If the system is quiet, you can try 'sync; sync; dd ...; fsck', but
something like 'tar cpf - | tar xpf -' is more likely to get you a
somewhat consistent view. Change /etc/fstab and reboot (you *can* try
mounting the new /var over the old one, but you'll want to play with
fstat -n to see which processes are still accessing the old /var.)
Of course, this isn't guaranteed to work. In particular, if something is
actually writing to /var, your view won't be consistent. Even more in
particular, don't try this with running databases.
Joachim
