Re: fsync on ext4 does not work

2011/12/19 Tomas Vondra <tv(at)fuzzy(dot)cz>

> On 19 Prosinec 2011, 16:52, Havasvölgyi Ottó wrote:
> > config:
> > fsync=on
> > sync_commit=on
> > wal_sync_method=fsync
>
> I don't think you need to set wal_sync_method, comment it out.
>

> > Even though the TPS in pgbench about 700 with 1 client.
> > I have tried other sync methods (fdatasync, open_sync), but all are
> > similar.
> > Should I disable write cache on HDD to make it work?
>
> Yes, disable that.
>
> > Have you any idea why?
>
> What scale factor have you used with pgbench? And how long are the pgbench
> runs? The smaller the data set, the more it will be affected by the write
> cache.
>

Scale factor was 1, client count 1, and ran it for 100 seconds. I just
wanted to check that the commit rate does not go beyond 120 (7200 rpm HDD).

> Tomas
>
>