Hi,
We have a postgres 9.3.x box, with 1.3TB free space, and our database of around 1.8TB. Unfortunately, we're struggling to back it up.
When we try a compressed backup with the following command:
pg_basebackup -D "$BACKUP_PATH/$TIMESTAMP" -Ft -Z9 -P -U "$DBUSER" -w
we get error:
pg_basebackup: could not get transaction log end position from server: ERROR: requested WAL segment 0000000400002B9F000000B4 has already been removed
This attempted backup reached 430GB before failing.
We were advised on IRC to try -Xs, but that only works with a plain (uncompressed) backup, and as you'll note from above, we don't have enough disk space for this.
Is there anything else we can do apart from get a bigger disk (not trivial at the moment)? Any best practice?
I suspect that setting up WAL archiving and / or playing with the wal_keep_segments setting might help, but as you can probably gather, I'd like to be sure that I'm doing something sane before I dive in.
Happy to give more detail if required.
Antony
