Yikes. I would not be able to sleep tonight if it were not for the BBU cache in front of these disks... diskchecker.pl consistently reported several examples of corruption post-power-loss (usually 10 - 30 ) on unprotected M500s/M550s, so I think it's pretty much open to debate what types of madness and corruption you'll find if you look close enough. G On 07 Jul 2015, at 16:59, Heikki Linnakangas <hlinnaka@xxxxxx> wrote: > > So it lies about fsync()... The next question is, does it nevertheless enforce the correct ordering of persisting fsync'd data? If you write to file A and fsync it, then write to another file B and fsync it too, is it guaranteed that if B is persisted, A is as well? Because if it isn't, you can end up with filesystem (or database) corruption anyway. > > - Heikki -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance