Re: no universally correct setting for fsync

Kevin Grittner <kevin.grittner@wicourts.gov>

From: "Kevin Grittner" <Kevin.Grittner@wicourts.gov>

To: Cédric Villemain <cedric.villemain.debian@gmail.com>, "Bernd Helmle" <mailings@oopsware.de>

Cc: "Andrew Dunstan" <andrew@dunslane.net>, <pgsql-hackers@postgresql.org>

Date: 2010-05-10T20:59:34Z

Lists: pgsql-hackers

Cédric Villemain<cedric.villemain.debian@gmail.com> wrote:
 
> On a recent pg_restore -j 32, with perc 6i with BBU, RAID10 8 hd,
> results were not so bas with fsync turn on. (XFS with nobarrier su
> and sw)
> -- deactivate fsync
> time pg_restore -U postgres -d foodb -j 32 foo.psql
> real    170m0.527s
> user    43m12.914s
> sys     1m56.499s
> -- activate fsync
> time pg_restore -U postgres -d foodb -j 32 foo.psql
> real    177m0.121s
> user    42m54.581s
> sys     2m0.452s
 
Wow.  In a situation where you save seven minutes (4%), it's hardly
worth turning off.
 
-Kevin