ZFS RaidZ2 with 24 drives?
Matt Simerson
matt at corp.spry.com
Thu Dec 24 03:15:50 UTC 2009
On Dec 23, 2009, at 12:26 PM, Solon Lutz wrote:
> Hi,
>
> I opted for two 12-disc raidz2.
> Reasons were: Space is more important than performance.
>
> But performance is very poor - have a look at the iostats - sometimes nothing really seems
> to happen for up to ten seconds, or very little data gets written. Might this be a problem
> of the amd64 system having only 4GB of RAM? Any tuneable sysctls? Enabling prefetch didn't help...:
When testing on a i386 system with only 4GB of ram, disabling prefetch did help. There are the settings I used, way back when...
$ cat /boot/loader.conf
#vm.kmem_size="1024M"
#vm.kmem_size_max="1024M"
#vfs.zfs.prefetch_disable=1
#vfs.zfs.arc_min="16M"
#vfs.zfs.arc_max="64M"
I ultimately worked around that problem by no longer using raidz2.
Matt
> capacity operations bandwidth capacity operations bandwidth
> pool used avail read write read write pool used avail read write read write
> ---------- ----- ----- ----- ----- ----- ----- ---------- ----- ----- ----- ----- ----- -----
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 1.23K 0 153M
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 0 0 510
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 0 0 510
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 835 0 104M
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 645 0 68.7M
> backup-7 1.23T 130G 0 0 0 0 store-1 616G 15.6T 0 0 0 0
> backup-7 1.23T 130G 474 0 59.3M 0 store-1 616G 15.6T 0 4 0 5.49K
> backup-7 1.23T 130G 494 0 61.8M 0 store-1 616G 15.6T 0 0 0 0
> backup-7 1.23T 130G 53 0 6.73M 0 store-1 617G 15.6T 0 19 0 39.4K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 30 0 140K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 33 0 72.8K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 65 0 162K
> backup-7 1.23T 130G 71 0 8.92M 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 636 0 79.4M 0 store-1 617G 15.6T 0 4 0 10.5K
> backup-7 1.23T 130G 485 0 60.6M 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 85 0 10.7M 0 store-1 617G 15.6T 0 15 0 39.9K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 17 0 40.4K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 31 0 73.3K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 62 0 156K
> backup-7 1.23T 130G 17 0 2.24M 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 189 0 23.6M 0 store-1 617G 15.6T 0 9 0 14.0K
> backup-7 1.23T 130G 2 74 133K 247K store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 12 0 17.5K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 1 0 255K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 100 0 12.6M
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 1012 0 126M
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 33 0 137K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 19 0 293K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 153 0 19.2M
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 109 0 13.7M
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 4 0 15.5K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 1.54K 0 188M
> backup-7 1.23T 130G 6 0 888K 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 556 0 69.5M 0 store-1 617G 15.6T 0 8 0 11.0K
> backup-7 1.23T 130G 500 0 62.5M 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 5 0 766K 0 store-1 617G 15.6T 0 16 0 30.4K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 29 0 136K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 38 0 84.7K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 57 0 145K
> backup-7 1.23T 130G 92 0 11.6M 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 497 0 62.1M 0 store-1 617G 15.6T 0 8 0 9.48K
> backup-7 1.23T 130G 534 0 66.7M 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 153 0 19.2M 0 store-1 617G 15.6T 0 12 0 12.0K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 26 0 101K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 34 0 76.3K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 62 0 155K
> backup-7 1.23T 130G 75 0 9.48M 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 690 0 86.3M 0 store-1 617G 15.6T 0 6 0 12.0K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 10 0 14.0K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 1 0 255K
> backup-7 1.23T 130G 0 0 0 0 store-1 617G 15.6T 0 0 0 0
>
>
>
>
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