Re: ZFS melting under postgres...

On Dec 12, 2007 6:58 PM, Hugo Silva <hugo_at_barafranca.com> wrote:
>
> Benjamin Close wrote:
> > Peter Losher wrote:
> >> Hi,
> >>
> >> As part of our testing 7.0/ZFS we tried putting it thru it's paces
> >> having ZFS act as our storage medium for some test pgsql db's (like for
> >> sqlgrey, etc) and in both BETA2 and BETA4 (amd64) we get the same
> >> results with a RAIDZ2 container:
> >>
> >> -=-
> >> Dec 12 14:24:12 nsa sqlgrey: fatal: setconfig error at
> >> /usr/local/sbin/sqlgrey line 186.
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad4 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad6 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad8 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad10 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad12 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad14 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad16 offset=3665128448 size=21504
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad18 offset=3665128448 size=21504
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad4 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad6 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad8 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad10 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad12 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad14 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad16 offset=3665128448 size=21504
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad18 offset=3665128448 size=21504
> >> Dec 12 16:49:53 nsa root: ZFS: zpool I/O failure, zpool=vault error=86
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad4 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad6 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad8 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad10 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad12 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad14 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad16 offset=3665128448 size=21504
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad18 offset=3665128448 size=21504
> >> Dec 12 16:49:53 nsa postgres[50527]: [5-1] PANIC:  could not write to
> >> log file 2, segment 53 at offset 7864320, length 8192: Input/output
> >> error
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad4 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad6 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad8 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad10 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad12 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad14 offset=3665128448 size=22016
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad16 offset=3665128448 size=21504
> >> Dec 12 16:49:53 nsa root: ZFS: checksum mismatch, zpool=vault
> >> path=/dev/ad18 offset=3665128448 size=21504
> >> Dec 12 16:49:53 nsa root: ZFS: zpool I/O failure, zpool=vault error=86
> >> Dec 12 16:49:53 nsa postgres[50596]: [1-1] FATAL:  the database system
> >> is starting up
> >> Dec 12 16:49:53 nsa kernel: pid 50527 (postgres), uid 70: exited on
> >> signal 6 (core dumped)
> >> -=-
> >>
> >> It basically corrupts the container from the inside until it fails
> >> completely (usually withing 24-48 hours depending on how busy the db is)
> >>
> >> I had thought it was a bad SATA replicator/controller, but we had that
> >> replaced w/ one from Supermicro.  So it's either the disks, or something
> >> in ZFS.  Anyone used ZFS to backend any db's (mysql or pgsql?)
> >>
> >> If you need more info, let me know...
> >>
> >>
> > Try turning of zil, whilst I don't use a db, I have zfs under high
> > load. I've found without zil turned off I see checksum corruption as
> > well:
> >
> > /boot/loader.conf
> >
> > vfs.zfs.zil_disable=1
> >
> > Cheers,
> >    Benjamin
>
> Wouldn't it be a bad idea to disable ZIL ?
>
> http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide#Disabling_the_ZIL_.28Don.27t.29

Yes. However, FreeBSD suffers from deadlocks under load if ZIL is enabled.

 -Kip