On Wed, Mar 22, 2017 at 10:25:24PM +0100, O. Hartmann wrote: > Am Wed, 22 Mar 2017 21:10:51 +0100 > Michael Gmelin <free...@grem.de> schrieb: > > > > On 22 Mar 2017, at 21:02, O. Hartmann <ohartm...@walstatt.org> wrote: > > > > > > CURRENT (FreeBSD 12.0-CURRENT #82 r315720: Wed Mar 22 18:49:28 CET 2017 > > > amd64) is > > > annoyingly slow! While scrubbing is working on my 12 GB ZFS volume, > > > updating /usr/ports takes >25 min(!). That is an absolute record now. > > > > > > I do an almost daily update of world and ports tree and have periodic > > > scrubbing ZFS > > > volumes every 35 days, as it is defined in /etc/defaults. Prts tree > > > hasn't grown much, > > > the content of the ZFS volume hasn't changed much (~ 100 GB, its fill is > > > about 4 TB > > > now) and this is now for ~ 2 years constant. > > > > > > I've experienced before that while scrubbing the ZFS volume, some > > > operations, even the > > > update of /usr/ports which resides on that ZFS RAIDZ volume, takes a bit > > > longer than > > > usual - but never that long like now! > > > > > > Another box is quite unusable while it is scrubbing and it has been > > > usable times > > > before. The change is dramatic ... > > > > > > > What do "zpool list", "gstat" and "zpool status" show? > > > > > > > zpool list: > > NAME SIZE ALLOC FREE EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT > TANK00 10.9T 5.45T 5.42T - 7% 50% 1.58x ONLINE - > > Deduplication is off right now, I had one ZFS filesystem with dedup enabled > > gstat: not shown here, but the drives comprise the volume (4x 3 TB) show 100% > busy each, > but one drive is always a bit off (by 10% lower) and this drive is walking > through all > four drives ada2, ada3, ada4 and ada5. Nothing unusual in that situation. But > the > throughput is incredible low, for example ada4: > > L(q) ops/s r/s kBps ms/r w/s kBps ms/w %busy Name > 2 174 174 1307 11.4 0 0 0.0 99.4| ada4 > > kBps (kilo Bits per second I presume) are peaking at ~ 4800 - 5000. On > another bos, this > is ~ 20x higher! Most time, kBps r and w stay at ~ 500 -600.
kilo Bytes. 174 rps is normal for general 7200 RPM disk. Transfer too low by every request is about 1307/174 = ~8 KB. Don't know root cause of this. I am see raid-z of 4 disk, 8*3 = ~24KB per record. May be compession enable and zfs use 128KB record size? For this case this is expected performance. Use 1MB and higher record size. _______________________________________________ email@example.com mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"