[OpenIndiana-discuss] [zfs-discuss] slow speed problem with a new SAS shelf

Sašo Kiselkov skiselkov.ml at gmail.com
Mon Jul 23 16:09:59 UTC 2012


Hi,

Have you had a look iostat -E (error counters) to make sure you don't
have faulty cabling? I've bad cables trip me up once in a manner similar
to your situation here.

Cheers,
--
Saso

On 07/23/2012 07:18 AM, Yuri Vorobyev wrote:
> Hello.
> 
> I faced with a strange performance problem with new disk shelf.
> We a using  ZFS system with SATA disks for a while.
> It is Supermicro SC846-E16 chassis, Supermicro X8DTH-6F motherboard with
> 96Gb RAM and 24 HITACHI HDS723020BLA642 SATA disks attached to onboard
> LSI 2008 controller.
> 
> Pretty much satisfied with it we bought additional shelf with SAS disks
> for VMs hosting. New shelf is Supermicro SC846-E26 chassis. Disks model
> is HITACHI HUS156060VLS600 (15K 600Gb SAS2).
> Additional controller LSI 9205-8e was installed in server and connected
> with JBOD.
> I connected JBOD with 2 channels and setup multi path first, but when i
> noticed performance problem i disabled multi path and disconnected one
> cable (for sure it is not multipath cause the problem).
> 
> Problem description follow:
> 
> Creating test pool with 5 pair of mirrors (new shelf, SAS disks)
> 
> # zpool create -o version=28 -O primarycache=none test mirror
> c9t5000CCA02A138899d0 c9t5000CCA02A102181d0 mirror c9t5000CCA02A13500Dd0
> c9t5000CCA02A13316Dd0 mirror c9t5000CCA02A005699d0 c9t5000CCA02A004271d0
> mirror c9t5000CCA02A004229d0 c9t5000CCA02A1342CDd0 mirror
> c9t5000CCA02A1251E5d0 c9t5000CCA02A1151DDd0
> 
> (primarycache=none) to disable ARC influence
> 
> 
> Testing sequential write
> # dd if=/dev/zero of=/test/zero bs=1M count=2048
> 2048+0 records in
> 2048+0 records out
> 2147483648 bytes (2.1 GB) copied, 1.04272 s, 2.1 GB/s
> 
> iostat when writing look like
>      r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device
>      0.0 1334.6    0.0 165782.9  0.0  8.4    0.0    6.3   1  86
> c9t5000CCA02A1151DDd0
>      0.0 1345.5    0.0 169575.3  0.0  8.7    0.0    6.5   1  88
> c9t5000CCA02A1342CDd0
>      2.0 1359.5    1.0 168969.8  0.0  8.7    0.0    6.4   1  90
> c9t5000CCA02A13500Dd0
>      0.0 1358.5    0.0 168714.0  0.0  8.7    0.0    6.4   1  90
> c9t5000CCA02A13316Dd0
>      0.0 1345.5    0.0 166669.3  0.0  9.0    0.0    6.7   1  92
> c9t5000CCA02A102181d0
>      1.0 1317.5    1.0 164456.9  0.0  8.5    0.0    6.5   1  88
> c9t5000CCA02A004271d0
>      4.0 1342.5    2.0 166282.2  0.0  8.5    0.0    6.3   1  88
> c9t5000CCA02A1251E5d0
>      0.0 1377.5    0.0 170515.5  0.0  8.7    0.0    6.3   1  90
> c9t5000CCA02A138899d0
> 
> Now read
> # dd if=/test/zero of=/dev/null  bs=1M
> 2048+0 records in
> 2048+0 records out
> 2147483648 bytes (2.1 GB) copied, 13.5681 s, 158 MB/s
> 
> iostat when reading
>      r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device
>    106.0    0.0 11417.4    0.0  0.0  0.2    0.0    2.4   0  14
> c9t5000CCA02A004271d0
>     80.0    0.0 10239.9    0.0  0.0  0.2    0.0    2.4   0  10
> c9t5000CCA02A1251E5d0
>    110.0    0.0 12182.4    0.0  0.0  0.1    0.0    1.3   0   9
> c9t5000CCA02A138899d0
>    102.0    0.0 11664.4    0.0  0.0  0.2    0.0    1.8   0  15
> c9t5000CCA02A005699d0
>     99.0    0.0 10900.9    0.0  0.0  0.3    0.0    3.0   0  16
> c9t5000CCA02A004229d0
>    107.0    0.0 11545.4    0.0  0.0  0.2    0.0    1.9   0  13
> c9t5000CCA02A1151DDd0
>     81.0    0.0 10367.9    0.0  0.0  0.2    0.0    2.2   0  11
> c9t5000CCA02A1342CDd0
> 
> Unexpected low speed! Note the busy column. When writing it about 90%,
> when reading it about 15%
> 
> Individual disks raw read speed (don't be confused with name change. i
> connect JBOD to another HBA channel)
> 
> # dd if=/dev/dsk/c8t5000CCA02A13889Ad0 of=/dev/null bs=1M count=2000
> 2000+0 records in
> 2000+0 records out
> 2097152000 bytes (2.1 GB) copied, 10.9685 s, 191 MB/s
> # dd if=/dev/dsk/c8t5000CCA02A1342CEd0 of=/dev/null bs=1M count=2000
> 2000+0 records in
> 2000+0 records out
> 2097152000 bytes (2.1 GB) copied, 10.8024 s, 194 MB/s
> 
> The 10-disks mirror zpool read slower than a single disk.
> 
> There is no tuning in /etc/system
> 
> I tried test with FreeBSD 8.3 live CD. Reads was the same (about
> 150Mb/s). Also i tried SmartOS, but it can't see disks behind LSI
> 9205-8e controller.
> 
> For compare this is speed from SATA pool (it consist of 4 6-disk raidz2
> vdev)
> #dd if=CentOS-6.2-x86_64-bin-DVD1.iso of=/dev/null bs=1M
> 4218+1 records in
> 4218+1 records out
> 4423129088 bytes (4.4 GB) copied, 4.76552 s, 928 MB/s
> 
>      r/s    w/s   kr/s   kw/s wait actv wsvc_t asvc_t  %w  %b device
>   13614.4    0.0 800338.5    0.0  0.1 36.0    0.0    2.6   0 914 c6
>    459.9    0.0 25761.4    0.0  0.0  0.8    0.0    1.8   0  22
> c6t5000CCA369D16860d0
>     84.0    0.0 2785.2    0.0  0.0  0.2    0.0    3.0   0  13
> c6t5000CCA369D1B1E0d0
>    836.9    0.0 50089.5    0.0  0.0  2.6    0.0    3.1   0  60
> c6t5000CCA369D1B302d0
>    411.0    0.0 24492.6    0.0  0.0  0.8    0.0    2.1   0  25
> c6t5000CCA369D16982d0
>    821.9    0.0 49385.1    0.0  0.0  3.0    0.0    3.7   0  67
> c6t5000CCA369CFBDA3d0
>    231.0    0.0 12292.5    0.0  0.0  0.5    0.0    2.3   0  18
> c6t5000CCA369D17E73d0
>    803.9    0.0 50091.5    0.0  0.0  2.9    0.0    3.6   1  69
> c6t5000CCA369D0EA93d0
> 
> PS. Before testing i flash last firmware and bios to LSI 9205-8e. It
> come with factory 9 version. I flashed version 13.5.
> Now I think that it was not worth such a hurry.
> Then i downgrade it to version 12. Read speed remains the same.
> Now controllers versions
> 
>  # ./sas2flash -listall
>  LSI Corporation SAS2 Flash Utility
>  Version 12.00.00.00 (2011.11.08)
>  Copyright (c) 2008-2011 LSI Corporation. All rights reserved
> 
>          Adapter Selected is a LSI SAS: SAS2008(B1)
> 
>  Num   Ctlr            FW Ver        NVDATA        x86-BIOS         PCI
> Addr
> 
> ----------------------------------------------------------------------------
> 
> 
>  0  SAS2008(B1)     12.00.00.00    0c.00.00.04    07.23.01.00 00:05:00:00
>  1  SAS2308_2(B0)   12.00.00.00    0c.00.00.04    07.23.01.00 00:84:00:00
> 
> Any suggestions or thoughts ?
> 
> 
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