Thread: Point in Time Recovery (WAL) archive_command

Hello List,

i am using the following archive command:
   archive_command = '/usr/bin/rsync -a -F /data/pgsql/%p
pgsql@pg-backup:/restore/walfiles/'

Which works perfectly so far. My problem now is, what happens if the
"pg-backup" server is down for some time and the archove command can
not copy the wal files to the destination anymore? Can i manually sync
the not transfered files? If yes, which ones do i need to copy?

Cheers,
Mario

ml ml <mliebherr99@googlemail.com> wrote:

> i am using the following archive command:
>    archive_command = '/usr/bin/rsync -a -F /data/pgsql/%p
> pgsql@pg-backup:/restore/walfiles/'
>
> Which works perfectly so far. My problem now is, what happens if the
> "pg-backup" server is down for some time and the archove command can
> not copy the wal files to the destination anymore? Can i manually
> sync the not transfered files? If yes, which ones do i need to copy?

The relevant part of the fine manual says:

"It is important that the archive command return zero exit status if
and only if it succeeded. Upon getting a zero result, PostgreSQL will
assume that the file has been successfully archived, and will remove
or recycle it. However, a nonzero status tells PostgreSQL that the
file was not archived; it will try again periodically until it
succeeds."

http://www.postgresql.org/docs/8.4/interactive/continuous-archiving.html#BACKUP-ARCHIVING-WAL

If you do that, you don't have to worry about any extra copying.  If
you don't, the files you need might be gone by the time the
connectivity recovers.

-Kevin