Re: [Iscsitarget-devel] [HELP]write in file-io mode cause a lot of I/O wait, perfomance is low

[Ming Z. <bla...@gm...>]

On Wed, 2008-10-29 at 10:45 +0800, hank.peng wrote:
> Hi, everybody:
> I am doing a performance test on my machine. Kernel version is
> 2.6.15.4, IET version is 0.4.15. I exported a sata disk to Windows and
> then doing IOmeter test.


try to use blockio. or search list archive for why.


> 
> #pvcreate /dev/sda
> #vgcreate Pool_disk1
> #lvcreate -L10G -n testiscsi Pool_disk1
> #cat /etc/ietd.conf
> Target iqn.2006-05.com.dahuatech:testiscsi.20081029094133
>         Lun 0 Path=/dev/Pool_disk1/testiscsi,Type=fileio,IOMode=wb
>         HeaderDigest  None,None
>         DataDigest    None,None
>         Wthreads      16
> On windows side, I use initiator to connect this target and create a
> partion fomated with NTFS. When doing IOMeter test, I first chose "4K;
> 0% Read; 0% random".
> The following is output of vmstat on my machine when test is going on.
> root@NSP-NAS:~# vmstat 1
> procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
>  r  b   swpd   free        buff        cache   si   so    bi    bo
>  in       cs     us sy id    wa
>  0  1      0    316932  143324   6788    0    0    62   291     68
>  667    0  5 94    1
>  2  1      0 314948     145208   6788    0    0  1892  4144   1111
> 7110  1  6  2    91
>  2  1      0 313088     146976   6788    0    0  1796     0     1015
> 6602  0  6  0    94
>  0  1      0 311476     148700   6788    0    0  1700  4094   1015
> 6369  0 11  0   89
>  0  1      0 309492     150540   6788    0    0  1836     0      1057
> 6699  0  5  0    95
>  0  1      0 307756     152272   6788    0    0  1728  4092   1038
> 6563  0  9   0   91
>  1  1      0 305896     154204   6788    0    0  1944     0       1098
>  7433  0  6  0    94
>  1  1      0 303788     156248   6788    0    0  2044  4097    1166
> 7520  0 14  0    86
>  1  1      0 301804     158176   6788    0    0  1940     0      1098
> 7381  0 11  0    89
>  2  1      0 299820     160148   6788    0    0  1976     0      1092
> 7334  1  7  0     92
>  1  1      0 297836     162044   6788    0    0  1900  4092    1109
> 7251  0  9  1    90
>  0  1      0 295976     163852   6788    0    0  1804     0       1049
>  6877  0  6  0    94
>  0  1      0 294116     165720   6788    0    0  1836  4092    1082
> 6973  0 10  0   90
>  0  1      0 292256     167608   6788    0    0  1908     0      1080
> 6984  0 10  1    89
>  0  1      0 290272     169560   6788    0    0  1932     0      1075
> 7099  0 10  0    90
> ....
> As you see, there is a lot of I/O wait. Another confusing thing is why
> there are some "bi" since I am doing 100% write?
> 
> 
-- 
never so busy...
http://www.linkedin.com/in/blackmagic02881