Date: Tue, 04 Nov 2014 09:06:42 +0000 From: Steven Hartland <killing@multiplay.co.uk> To: freebsd-stable@freebsd.org Subject: Re: ARC size limit Message-ID: <54589722.3080803@multiplay.co.uk> In-Reply-To: <3B70EA0C-0976-49D6-8418-6B5D22ED7E65@gmail.com> References: <3B70EA0C-0976-49D6-8418-6B5D22ED7E65@gmail.com>
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You need https://svnweb.freebsd.org/base?view=revision&revision=272875 On 04/11/2014 06:29, George Kola wrote: > Hi All, > This is my first post to freebsd-stable fresh of Meet BSD California 2014. We are switching our entire production to FreeBSD. Our storage servers have 256 GB of RAM , 4 TB of SSD and 40 TB of spinning disks. We are running ZFS root and the SSD is configured as L2ARC. We are running FreeBSD 10.1 RC3 > I am finding that on all our machines, ARC is somehow limited to < 64 GB of memory and we have a huge inactive memory (180 G). The surprising thing is that ARC seems to have almost the same limit (< 64 GB) on all of our storage boxes and ARC is not growing even though L2ARC hit shows that there is advantage in growing ARC. > Any help/pointers is appreciated. > What I am trying to do is to tune ZFS for our workload. We are hoping that we get a high hit rate. > Thanks to Justin Gibbs and Allan Jude for initial pointers and help. They suggested posting to the mailing list to get further help. > > I have pasted top output and zfs-stats output below and yes UMA is enabled. > > Thanks, > George > > > > top > last pid: 27458; load averages: 3.30, 5.42, 5.34 up 6+09:59:30 05:38:49 > 71 processes: 1 running, 70 sleeping > CPU: 4.2% user, 0.0% nice, 4.6% system, 0.2% interrupt, 90.9% idle > Mem: 11G Active, 181G Inact, 52G Wired, 1368M Cache, 4266M Free > ARC: 47G Total, 1555M MFU, 41G MRU, 35M Anon, 3984M Header, 709M Other > Swap: 64G Total, 2874M Used, 61G Free, 4% Inuse > > > > sysctl vfs.zfs.zio.use_uma > vfs.zfs.zio.use_uma: 1 > > > > > zfs-mon -a output > > ZFS real-time cache activity monitor > Seconds elapsed: 62 > > Cache hits and misses: > 1s 10s 60s tot > ARC hits: 124 126 103 101 > ARC misses: 35 46 29 28 > ARC demand data hits: 55 90 61 61 > ARC demand data misses: 20 32 18 17 > ARC demand metadata hits: 69 36 42 40 > ARC demand metadata misses: 9 13 10 9 > ARC prefetch data hits: 0 0 0 0 > ARC prefetch data misses: 6 1 1 1 > ARC prefetch metadata hits: 0 0 0 0 > ARC prefetch metadata misses: 0 0 0 0 > L2ARC hits: 16 28 14 14 > L2ARC misses: 19 18 15 14 > ZFETCH hits: 592 2842 2098 2047 > ZFETCH misses: 308 1326 507 494 > > Cache efficiency percentage: > 10s 60s tot > ARC: 73.26 78.03 78.29 > ARC demand data: 73.77 77.22 78.21 > ARC demand metadata: 73.47 80.77 81.63 > ARC prefetch data: 0.00 0.00 0.00 > ARC prefetch metadata: 0.00 0.00 0.00 > L2ARC: 60.87 48.28 50.00 > ZFETCH: 68.19 80.54 80.56 > > > > > zfs-stats -a output > > ZFS real-time cache activity monitor > Seconds elapsed: 62 > > Cache hits and misses: > 1s 10s 60s tot > ARC hits: 124 126 103 101 > ARC misses: 35 46 29 28 > ARC demand data hits: 55 90 61 61 > ARC demand data misses: 20 32 18 17 > ARC demand metadata hits: 69 36 42 40 > ARC demand metadata misses: 9 13 10 9 > ARC prefetch data hits: 0 0 0 0 > ARC prefetch data misses: 6 1 1 1 > ARC prefetch metadata hits: 0 0 0 0 > ARC prefetch metadata misses: 0 0 0 0 > L2ARC hits: 16 28 14 14 > L2ARC misses: 19 18 15 14 > ZFETCH hits: 592 2842 2098 2047 > ZFETCH misses: 308 1326 507 494 > > Cache efficiency percentage: > 10s 60s tot > ARC: 73.26 78.03 78.29 > ARC demand data: 73.77 77.22 78.21 > ARC demand metadata: 73.47 80.77 81.63 > ARC prefetch data: 0.00 0.00 0.00 > ARC prefetch metadata: 0.00 0.00 0.00 > L2ARC: 60.87 48.28 50.00 > ZFETCH: 68.19 80.54 80.56 > > > > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"
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