On Mon, Dec 2, 2013 at 6:22 AM, Spiros Ioannou <siv...@inaccess.com> wrote:
> We are dumping a 4TB postgres database using pg_dump. The source is on a > copy-on-write snapshot filesystem, and the target is an external drive. > > While the pg_dump is running we get about 4-5MB/sec writes on the > filesystem where postgresql data is (iostat), and specifically inside the > base/ directory. > > Since the only query running on this DB is the COPY initiated from pg_dump > which only reads data, who is writing data to postgres datafiles? > It is probably setting "hint bits" on the tuples it is visiting. > > We need to find a way to make postgres stop writing because the source > copy-on-write filesystem gets filled up before the dump is finished. > Vacuum the system before taking the snapshot. > > Postgresql version is 8.4, vacuum is not running (autovacuum = off), OS is > debian 6. > Since autovacuum is off, what are you doing about vacuuming? Cheers, Jeff
