postgres vacuumdb

[Gorgon@]

Hi folks,

Any recommendations on the best way to setup a cronjob for the vacuumdb utility for Postgres?

I know virtually nothing about postgres. I setup a cronjob a while back to run the vacuumdb utility which runs nightly as such:

/usr/bin/vacuumdb -a -q -U root

It seems to have been working fine until I got this message last night:

WARNING: Some databases have not been vacuumed in over 2 billion transactions.
You may have already suffered transaction-wraparound data loss.

According to the postgres docs, a regular vacuum should already be taking care of this. So I'm assuming I'm not using the correct options.

Any suggestions are appreciated.

Thanks,
mikeS