Date: Tue, 13 Apr 2010 12:14:45 +0400 From: "Alexandr D. Sergeev" <ales@ripn.net> To: kmacy@freebsd.org Cc: freebsd-performance@freebsd.org Subject: Re: Extreme performance falling on ZFS by durable operation of a server Message-ID: <4BC427F9.7090703@ripn.net> In-Reply-To: <j2v82c4140e1004121256pedf4846fjcfd11f2643e217f3@mail.gmail.com> References: <20100408153257.GA35557@runo.ripn.net> <y2k82c4140e1004081314s7a44ed0g1b833dc1e8a011a7@mail.gmail.com> <20100409024409.GA1602@runo.ripn.net> <20100412091136.GE61157@runo.ripn.net> <j2v82c4140e1004121256pedf4846fjcfd11f2643e217f3@mail.gmail.com>
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K. Macy пишет: > 8-STABLE is definitely better, but you should also set arc_min to at > least 384M-512M. I'm not sure that arc_min is even honored under 7.2. Thanks for advice! And I also not sure, because now settings is: vfs.zfs.arc_min: 1073741824 vfs.zfs.arc_max: 1610612736 but vmstat -m shows: solaris 1098941 622231K - 6443745881 16,32,64,128,256,512,1024,2048,4096 > > -Kip > > > On Mon, Apr 12, 2010 at 2:11 AM, Alexandr D. Sergeev <ales@ripn.net> wrote: >> Whether there are any ideas about the reasons of such problems? >> >> Whether transition to FreeBSD 8.0 RELEASE / STABLE can help? >> ZFS in it is declared as "bug free" >> >> On Fri, Apr 09, 2010 at 06:44:09AM +0400, Alexandr D. Sergeev wrote: >>> On Thu, Apr 08, 2010 at 01:14:42PM -0700, K. Macy wrote: >>>> Hi Alexandr, >>> Hi Kip, >>> >>>> - How much memory do you have? >>> 4Gb. >>> Applications consume a lot of memory, is partially used swap (~1Gb, but without active i/o). >>> >>> We have planned increase in memory to 16G >>> >>>> - What are your ARC settings? >>> Settings is default, that recommended for amd64 kernel. >>> But I am not assured that it is optimal. >>> Thus sysctl variables are automatically sets to: >>> vfs.zfs.arc_max ~800Mb >>> vfs.zfs.arc_mim ~128Mb >>> >>> Now the next reboot was required. >>> Together with which following settings have been made: >>> >>> vm.kmem_size=2048M >>> vfs.zfs.arc_max=1536M >>> vfs.zfs.arc_min=1024M >>> vfs.zfs.vdev.cache.size=64M >>> >>> Let's look, as it will affect. >>> >>> However there is confidence that no problem at a size of ARC. >>> Even at 200Mb ARC, productivity should not fall so strongly. >>> >>>> Thanks, >>>> Kip >>>> >>>> On Thu, Apr 8, 2010 at 8:32 AM, Alexandr D. Sergeev <ales@ripn.net> wrote: >>>>> Hi, all! >>>>> >>>>> There are problems with a server on FreeBSD 7.2 CURRENT (6 Jul 2009), carrying out the task of mail server SMTP, IMAP. >>>>> >>>>> Messages are stored in maildirs on file system ZFS (mirror of 2 SAS 3k drives). >>>>> Dovecot is used as IMAP server. >>>>> >>>>> After reboot the system works perfectly, however, somewhere in a month, at the same load, arise periodic long delays at opening of new letters. >>>>> >>>>> Judging by output iostat -x -w 1, during these moments the disk subsystem is strongly loaded. >>>>> %busy disks comes nearer to 100 %. Readings nearby 300 per sec prevail. and approx. 10MBytes per sec. >>>>> >>>>> Somebody can advise, what diagnostics needed, for understanding of the reason of problems? >>>>> >>>>> There is an opinion that a problem with ZFS. >>>>> >>>>> Probably, it does not have enough memory. Because during the periods of occurrence of a problem, ARC is have less 300MB: >>>>> >>>>> vmstat -m >>>>> ... >>>>> solaris 1245732 274745K - 25872717949 16,32,64,128,256,512,1024,2048,4096 >>>>> ... >>>>> >>>>> Or it is bug of ZFS implementation. >>>>> >>>>> -- >>>>> Best regards, >>>>> Alexandr D.Sergeev >>>>> _______________________________________________ >>>>> freebsd-performance@freebsd.org mailing list >>>>> http://lists.freebsd.org/mailman/listinfo/freebsd-performance >>>>> To unsubscribe, send any mail to "freebsd-performance-unsubscribe@freebsd.org" >>>>> >> -- >> Best regards, >> Alexandr D.Sergeev >> _______________________________________________ >> freebsd-performance@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-performance >> To unsubscribe, send any mail to "freebsd-performance-unsubscribe@freebsd.org" >> -- Best regards, Alexandr D.Sergeev
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