Date: Fri, 14 Dec 2007 16:08:19 +0100 From: Michael Rebele <m.rebele@web.de> To: freebsd-current@freebsd.org Subject: Re: 7.0-Beta 3: zfs makes system reboot Message-ID: <47629C63.7010204@web.de>
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Hello, replying my own message is a funny thing ;-) This message has more informational character than it is a error report. > Michael Rebele <m.rebele@web.de> wrote: > Von: m.rebele@web.de > Gesendet: 03.12.07 15:54:59 > An: freebsd-current@freebsd.org > Betreff: Re: 7.0-Beta 3: zfs makes system reboot > > Alexandre Biancalana wrote: > > On Nov 30, 2007 2:27 PM, Michael Rebele <m.rebele@web.de> wrote: > >> 4. The applied kernel settings > >> kern.maxvnodes="400000" > >> vm.kmem_size_max="512M" > >> vm.kmem_size="512M" > >> > >> 5. Output from zpool > >> [root@zfs /root]# zpool status > >> pool: tank > >> state: ONLINE > >> scrub: none requested > >> config: > >> > >> NAME STATE READ WRITE CKSUM > >> tank ONLINE 0 0 0 > >> ad4s1g ONLINE 0 0 0 > >> > >> errors: No known data errors > >> > >> [kmem_map too small error] > > > > Have you tried this patch > > http://people.freebsd.org/~pjd/patches/vm_kern.c.2.patch ? > I've applied the mentioned patch to the Beta3. Now the iozone-Benchmark runs through. Fine - be warned, on my machine it took about 30 hours (a 3GHz DualCore and a 160GB SATA HD w. 10000rpm). After the first successful run on a ZFS since my first try i tried the next step. Three parallel iozone (for your reference, here's again the setup: iozone -R -a -z -b filez-512M.wks -g 4G -f testile) runs on the mentioned machine. Nearly 5 days everything went fine, but then the system made a reboot. Unfortunately there's no log and the reboot happened in the night. Though, i don't really know the reason for this. I guess, the kmem_map error is the cause, because the symptoms are the same as on the BETA3-system before the applied patch. The last output i have from the benchmark, showed that the file size were in the 4GB area with a reclen in the 8192 area (well, short before iozone should finish). The problem is to track down the stuff, as it may took quite long until the error occurs - or lets say it better, even on a quite fast machine, iozone is quite slow. But the problem is not the CPU, it's the HD. Maybe somebody with access to a fast HD-Array can investigate this again. My conclusions to my tests: 1. You should really apply the mentioned patch if you plan to use ZFS on your Box for more than just testing and experimenting (well, ZFS is marked as that, though - you're warned). The memory/kernel parameter tuning recommendations helped me not really. 2. With the applied patch, ZFS seems quite robust for the average use. Maybe, there's a problem with a bigger load under some (rare?) circumstances. 3. The patch should find his way to the 'regular' kernel sources (or is it even in BETA4?). A big thanks to Pawel Jakub Dawidek for his great job. Michael -- Die Erde ist die Irrenanstalt des Universums. Public Key: http://sks.keyserver.penguin.de:11371/pks/lookup?op=get&search=0x5D0A2BC3CEB 3F472
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