On Fri, Mar 12, 2021 at 10:34 AM Thomas Munro wrote:
> It looks like your system is performing very badly for some other
> reason, so that synchronous I/O waits are only a small proportion of
> the time, and thus fsync=off doesn't speed things up very much. I'd
> look into profiling the system to
On Fri, Mar 12, 2021 at 10:33:29PM +1300, Thomas Munro wrote:
> On Fri, Mar 12, 2021 at 10:09 PM Luca Ferrari wrote:
> >fdatasync 16269.365 ops/sec 61 usecs/op
> >fsync 8471.429 ops/sec 118 usecs/op
>
> > Non-sync'ed 8k
On Fri, Mar 12, 2021 at 10:09 PM Luca Ferrari wrote:
>fdatasync 16269.365 ops/sec 61 usecs/op
>fsync 8471.429 ops/sec 118 usecs/op
> Non-sync'ed 8kB writes:
>write278484.510 ops/sec
On Thu, Mar 11, 2021 at 3:29 PM Bruce Momjian wrote:
>
> You should really be running pg_test_fsync for this kind of testing.
>
Sorry Bruce, but it is not clear to me: pg_test_fsync compares
different fsync implementations, but not the fsync on/off setting of a
cluster.
Now, pg_test_fsync report
On Tue, Feb 23, 2021 at 12:57:22PM +0100, Luca Ferrari wrote:
> On Tue, Feb 23, 2021 at 8:46 AM Luca Ferrari wrote:
> > I'm using sata disks, not scsi. Assuming I'm not looking at the wrong
> > parameter, I wil attach a scsi disk to do the same test and see if
> > something changes.
>
> I've test
On Tue, Feb 23, 2021 at 8:46 AM Luca Ferrari wrote:
> I'm using sata disks, not scsi. Assuming I'm not looking at the wrong
> parameter, I wil attach a scsi disk to do the same test and see if
> something changes.
I've tested the same version of PostgreSQL, same benchmark, on a scsi
disk. However
On Mon, Feb 22, 2021 at 10:38 PM Thomas Munro wrote:
> Do you have WCE enabled? In that case, modern Linux file systems
> would do a synchronous SYNCHRONIZE CACHE for our WAL fdatasync(), but
> FreeBSD UFS wouldn't as far as I know. It does know how to do that
> (there's a BIO_FLUSH operation, a
On Tue, Feb 23, 2021 at 5:49 AM Luca Ferrari wrote:
> I'm running a virtual machine with FreeBSD 12.2, PostgreSQL 12.5 and
> UFS as filesystem.
> I was experimenting with fsync = off and pgbench, and I see no
> particular difference in tps having fsync enabled or disabled.
> Now, the same tiny tes
Hi all,
I'm running a virtual machine with FreeBSD 12.2, PostgreSQL 12.5 and
UFS as filesystem.
I was experimenting with fsync = off and pgbench, and I see no
particular difference in tps having fsync enabled or disabled.
Now, the same tiny test on a linux box provides a 10x tps, while on
FreeBSD i
