mpt driver patch

[J.D. Bronson]

At 02:07 PM 06/04/2004, Jan_Rybensky at env.cz wrote:
>Hi All,
>
>as well as the others I've encoutered serious performace problems with IM
>volumes on LSI 1030 controller. It's because the mpt driver is unable to
>detect hidden disks of the IM volumes and initialize them. That disks
>operates at default SCSI speed and slows the whole volume.
>This patch is far from perfect (not performs full DV), but it solves the
>performance issues. It seems to be stable, but it's tested only on IBM
>version of controller (on-board controllers of xSeries 335, 345).
>
>There is other issue I'm unable to solve: although all discs operating at
>proper speeds, the resync of mirrored disks is still very slow. The
>controller probably needs additional initializations, but I'm unable to
>trace them in linux driver. Can anybody help? Any suggestions are
>welcomed.
>
>Here is diff against 4.9-REL mpt sources (it works well on 4.10-REL too)
>and a tarball of the whole mpt directory from /sys/dev with patched driver
>sources is here: http://mpt-freebsd.env.cz.
>
>Many thanks for any feedback.
>
>         Jan Rybensky

I have seen this exact same behavior under 5.2.1 ...I have the LSI 20320R 
card installed. Using normal setup - this card works well and the speeds 
are as expected:

da0 at mpt0 bus 0 target 0 lun 0
da0: <SEAGATE ST336607LW 0007> Fixed Direct Access SCSI-3 device
da0: 320.000MB/s transfers (160.000MHz, offset 63, 16bit), Tagged Queueing 
Enabled
da0: 35003MB (71687372 512 byte sectors: 255H 63S/T 4462C)


however, like you pointed out - the mirroring is atrocious. It took over 
5hrs to fully sync a mirror (RAID-1). Then when I rebooted, the performance 
was less than 2MB/sec on any transfers to/from the machine.

As long as the mirror is not active, the card+drives seem to work just fine.

FWIW, setting up a mirror on this same card+drives under solaris x86, works 
perfect and resync's in just over 2hrs.







-- 
J.D. Bronson
Aurora Health Care // Information Services // Milwaukee, WI USA
Office: 414.978.8282 // Email: jd at aurora.org // Pager: 414.314.8282