Re: Should a DB vacuum use up a lot of space ?

Philippe Girolami <philippe(dot)girolami(at)mosaik(dot)com> writes:
> Weve got a 16TB database thats run up against the wrap-around tx id issue (despite running auto-vacuum):
> ERROR: database is not accepting commands to avoid wraparound data loss in database "public"
> HINT: Stop the postmaster and use a standalone backend to vacuum that database.
> The message says to VACUUM the whole database so weve dropped down to single user mode and issued a vacuum verbose command on the backend

> 2) File system usage is going steadily up (3TB over the past 9
> hours). Why is that ?

Probably because there's no background process to issue auto-checkpoints
and thereby recover WAL space.

I'd try doing a control-C on the VACUUM, then a CHECKPOINT, then start
over. You might have to vacuum large tables individually and checkpoint
after each one.

regards, tom lane