On Wed, Oct 15, 2008 at 8:58 AM, Ivan Voras <ivoras@xxxxxxxxxxx> wrote: > 2008/10/15 Aidan Van Dyk <aidan@xxxxxxxxxxx>: >> * Ivan Voras <ivoras@xxxxxxxxxxx> [081015 10:05]: >> >>> So, pg_start_backup() freezes the data at the time it's called but still >>> data and xlog are changed, in a different way that's safe to backup? Why >>> not run with pg_start_backup() always enabled? >> >> I think your missing the whole point of "pg_start_backup()". >> pg_start_backup()" is *part* of a full PITR/backup run. i.e. you use it >> when you have an archive command working as well. It's *not* mean tto >> just allow you to do a filesystem copy inside a running data directory. > > Possibly - that's why I'm sticking to this thread :) My context is > doing full filesystem-only copies/backups of the database (xlogs & > all) - is pg_start_backup() applicable? Just an FYI, there are some issues with using filesystems that support snapshots, depending on the OS / filesystem. For instance, the LVM, which linux uses that allows snapshots, has issues with write barriers and also has a maximum throughput of about 300Meg/second. It's all a trade-off, but I don't run my db files on LVM because of those two problems. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
