Date: Mon, 9 Aug 2010 01:23:04 +0800 From: "Alex V. Petrov" <alexvpetrov@gmail.com> To: Jeremy Chadwick <freebsd@jdc.parodius.com> Cc: freebsd-stable@freebsd.org Subject: Re: zpool - low speed write Message-ID: <201008090123.04823.alexvpetrov@gmail.com> In-Reply-To: <20100805061959.GA92106@icarus.home.lan> References: <201008042008.25679.alexvpetrov@gmail.com> <201008051409.57751.alexvpetrov@gmail.com> <20100805061959.GA92106@icarus.home.lan>
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В сообщении от 5 августа 2010 14:19:59 вы написали: > > Can you please remove use of the zpool entirely (e.g. zpool destroy > tank) and do a write test to each disk itself? E.g.: > > dd if=/dev/zero of=/dev/ad8 bs=64k count=1000000 > dd if=/dev/zero of=/dev/ad10 bs=64k count=1000000 > dd if=/dev/zero of=/dev/ad12 bs=64k count=1000000 > > I don't recommend using large block sizes (e.g. bs=1M, bs=3M). dd if=/dev/zero of=/dev/ad8 bs=64k count=1000000 1000000+0 records in 1000000+0 records out 65536000000 bytes transferred in 604.849406 secs (108350937 bytes/sec) dd if=/dev/zero of=/dev/ad10 bs=64k count=1000000 1000000+0 records in 1000000+0 records out 65536000000 bytes transferred in 757.755459 secs (86487005 bytes/sec) dd if=/dev/zero of=/dev/ad12 bs=64k count=1000000 1000000+0 records in 1000000+0 records out 65536000000 bytes transferred in 604.857282 secs (108349526 bytes/sec) > If all of the above dds show good/decent throughput, then there's > something strange going on with ZFS. If this is the case, I would > recommend filing a PR and posting to freebsd-fs about the problem, > pointing folks to this thread. > > If all of the dds show bad throughput, then could you please do the > following: > > - Provide vmstat -i output > - Install ports/sysutils/smartmontools and run smartctl -a /dev/ad8, > smartctl -a /dev/ad10, and smartctl -a /dev/ad12 > > If only one of the dds shows bad throughput, then please: > > - Install ports/sysutils/smartmontools and run smartctl -a /dev/XXX, > where XXX is the disk which has bad throughput > - Try making a ZFS pool with all 3 disks, but then do "zpool offline > tank XXX" and then re-attempt the following dd: > dd if=/dev/zero of=/tank/test.zero bs=64k count=1000000 > And see what throughput looks like. > > Thanks. ----- Alex V. Petrovhome | help
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