On Mon, Jan 26, 2015 at 05:41:59PM -0500, Stephen Frost wrote: > I've thought about it a fair bit actually and I agree that there is some > risk to using rsync for *incremental* base backups. That is, you have > a setup where you loop with: > > pg_start_backup > rsync -> dest > pg_stop_backup > > without using -I, changing what 'dest' is, or making sure it's empty > every time. The problem is the 1s-level granularity used on the > timestamp. A possible set of operations, all within 1s, is: > > file changed > rsync starts copying the file > file changed again (somewhere prior to where rsync is at) > rsync finishes the file copy > > Now, this isn't actually a problem for the first time that file is > backed up- the issue is if that file isn't changed again. rsync won't > re-copy it, but that change that rsync missed won't be in the WAL > history for the *second* backup that's done (only the first), leading to > a case where that file would end up corrupted.
Interesting problem, but doesn't rsync use sub-second accuracy? -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
