Autovacuum ro prevent wraparound

I'm running PostgreSQL 8.4 on Ubuntu. While Postgres was do three autovacuums (to prevent wraparound) on three really large tables the root (/) directory filled to 100%. The filesystem for Postgres (/dev/mapper/db_vg-db_lv mounted on /db) has 56% of its space available. While Postgres was running, as soon as I'd free up some space in the root file system, some process would gobble it up. I stopped the Postgres service and immediately 7.5 GB freed up in the root filesystem.

Does Postgres use disk space outside of its own filesystem/directory tree? Is there a setting in the conf file so this can be directed to another filesystem (such as the /db)?

Thanks,

Steve Erickson
Senior Developer

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