How I can automate postgres DB backing up?

[Bruno Wolff III]

On Mon, Nov 05, 2007 at 20:14:02 +0700,
  Strong <strong_yethumble at pochta.ru> wrote:
> I have several DBs in single claster. When I make
> 
> pg_dumpall -U postgres >file
> 
> it asks me for password exact times the number DBs I have. Even to do
> that manualy, it sucks. But I want to go even farther: how I can
> automate the process to put into cron?

You can authenticate based on the peers uid since you are running the command
on the server. The files where you set this up are pg_hba.conf and
pg_ident.conf in /var/lib/pgsql/data. You can also use a ~/.pgpass file,
but using the uid base authentication is probably safer.

Once you do this you should be able to just put the dumpall command in cron.
Though you might also want to do some sanity checking to make sure the dump
succeeded (in case the disk filled up or something) and send a message
if things look wrong.