how to limit SCSI TCQ depth in FreeBSD?

[Chris Dillon]

On Fri, 11 Jun 2004, Herve Boulouis wrote:

> Le 11/06/2004 à 11:47, Frantisek Rysanek a écrit:
>> Dear SCSI experts and FreeBSD veterans,
>>
>> I'm looking for advice with an apparently simple SCSI issue: how do 
>> I set a maximum TCQ depth in FreeBSD?
>
> I'm no kernel guru but maybe adding an entry to the xpt_quirk_table 
> in sys/cam/cam_xpt.c for your disk would solve the problem ?

The first thing you should do is upgrade the firmware on the drive and 
see if that solves the problem.  If not, add an entry to the quirk 
table.  You can also use camcontrol to limit the maximum number of 
transactions sent to the drive concurrently.  To set the maximum queue 
depth on da0 to 32:

camcontrol tags da0 -N 32


-- 
  Chris Dillon - cdillon(at)wolves.k12.mo.us
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Q: Because it reverses the logical flow of conversation.
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