Date: Mon, 12 Apr 2010 12:56:09 -0700 From: "K. Macy" <kmacy@freebsd.org> To: "Alexandr D. Sergeev" <ales@ripn.net> Cc: freebsd-performance@freebsd.org Subject: Re: Extreme performance falling on ZFS by durable operation of a server Message-ID: <j2v82c4140e1004121256pedf4846fjcfd11f2643e217f3@mail.gmail.com> In-Reply-To: <20100412091136.GE61157@runo.ripn.net> References: <20100408153257.GA35557@runo.ripn.net> <y2k82c4140e1004081314s7a44ed0g1b833dc1e8a011a7@mail.gmail.com> <20100409024409.GA1602@runo.ripn.net> <20100412091136.GE61157@runo.ripn.net>
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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. -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=3D2048M >> vfs.zfs.arc_max=3D1536M >> vfs.zfs.arc_min=3D1024M >> vfs.zfs.vdev.cache.size=3D64M >> >> 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> wr= ote: >> > > 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 mon= th, 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 subs= ystem is strongly loaded. >> > > %busy disks comes nearer to 100 %. Readings nearby 300 per sec preva= il. and approx. 10MBytes per sec. >> > > >> > > Somebody can advise, what diagnostics needed, for understanding of t= he 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, =A0ARC is have less 300MB: >> > > >> > > vmstat -m >> > > ... >> > > =A0 =A0 =A0solaris 1245732 274745K =A0 =A0 =A0 - 25872717949 =A016,3= 2,64,128,256,512,1024,2048,4096 >> > > ... >> > > >> > > 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@fr= eebsd.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" >
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