iscsi_initiator 2.2.2 slow to write and read

[Jiansong Liu]

On Wed, Jul 8, 2009 at 1:36 AM, Gary Palmer <gpalmer at freebsd.org> wrote:

> On Tue, Jul 07, 2009 at 07:05:03PM +0800, Jiansong Liu wrote:
> > Hello All,
> >
> > I downloaded the latest iscsi_initiator 2.2.2 from Danny's FTP,
> > and compile kernel and iscontrol with 7.2 STABLE GENERIC config, only got
> > about 800KB/Sec speed to a DELL MD3000i disk array, I searched in
> > this malling list and found a patch, but it seems is not for this version
> > (2.2.2), any advice would be great appreciated.
> >
> > here are some details about my system:
> >
> > # sysctl net.iscsi
> > net.iscsi.driver_version: 2.2.2
> > net.iscsi.isid: ???DIB00
> > net.iscsi.sessions: 1
> > net.iscsi.0.targetname:
> > iqn.1984-05.com.dell:powervault.md3000i.60024e80004e71a9000000004a011120
> > net.iscsi.0.targeaddress: 192.168.4.182
> > net.iscsi.0.stats: recv=594 sent=594 flags=0x0000039f pdus-alloc=16
> > pdus-max=16 cws=426 cmd=157 exp=157 max=300 stat=159 itt=157
> > net.iscsi.0.douio: 0
> > net.iscsi.0.pid: 754
> >
> > # cat /etc/iscsi.conf
> > scpstorage01 {
> >         initiatorname =iqn.2005-01.il.ac.huji.cs::static01.com
> >         TargetName
> >
>  =iqn.1984-05.com.dell:powervault.md3000i.60024e80004e71a9000000004a011120
> >         TargetAddress =192.168.4.182:3260,1
> >          tags =4
> > }
>
> I'm no expert, but if that "tags" line refers to SCSI tags then that
> number is too small.  Try increasing it and see if that helps to
> address the problem.
>
> Regards,
>
> Gary
>

Hi Gary,

Thanks for the advice, I have tried set tags to 32 and 64,
but it could not get more performance on IO (90MB write and 56MB read).
I think the writing is good enough for my application, but the reading still
is a problem.

# dd if=/home/mogdata/test.foo of=/dev/null
2048000+0 records in
2048000+0 records out
1048576000 bytes transferred in 17.670549 secs (59340318 bytes/sec)

Best regards,
Liu Jiansong