Re: Backup is too slow

John Jensen wrote:
> Hi Greg & others.
> I run this on a 4 cpu smp box (Dell PE6650+EMC AX100) so I already
> offload pg_dump, gzip and split to other cpu's. Top confirms this:
> postmaster = 95% cpu ie. it uses one cpu completely. Unless I can get
> postmaster to do less work (that's what I'm looking for) or run multiple
> threads (not likely) that's about the best I can get.
>
> The job is clearly cpu bound in the postmaster process.

Hmmm, when I upgraded my Opteron box to 64-bit linux, my dump->gzip ran
twice as fast which told me the gzip was a bit part of the CPU usage.
Dunno what else you can do to make it run faster. My backups -- even on
64-bit -- still take 20 minutes on a 30GB DB.

>
> I'm a bit reluctant to go into the snapshot option You outline. It
> looks a bit tricky but if no other options are on hand then I'll have to
> bite the bullet.

Snapshot is much easier if you use LVM. No need to do any postgres
trickery. Just freeze the volume at the kernel level.