From: Bernd Schubert <bs@q-leap.de>
Subject: need help to suspend a device
Date: Wed, 5 Dec 2007 14:43:31 +0100
Message-ID: <200712051443.32176.bs@q-leap.de>
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Sender: linux-scsi-owner@vger.kernel.org
To: linux-scsi@vger.kernel.org, "Moore, Eric" <Eric.Moore@lsi.com>

Hi,

I need some help with device suspending or something similar to this.

Problem description: We have many many Infortrend sata-to-scsi-raid systems 
here, connected to several server systems with LSI2230 HBAs.
Now the problem is, that these Infortrend boxes sometimes suffer from some 
kind of hick-up, sometimes due to the reboot of second server connected to 
the very same Infortrend box and sometimes just for no obvious reason. 

As far I can presently see it, the best would be to suspend any i/o, commands, 
etc to the troublesome box for about 30s to 60s and just wait and then to 
repeat the last command.
However, presently the scsi-layer/driver will immediately begin a domain 
validation and then do a scsi-reset. Unfortunately this will cause even more 
trouble. Sometimes this works, in more cases it will end in an i/o error and 
in most cases these domain validations and scsi-resets will go into an 
endless loop and eventually the Infortrend raids will be so confused that 
their scsi-controller will crash.

I'm already looking for some hours through the scsi and mpt functions, but so 
far didn't find a good way to put commands to a scsi-device to sleep for some 
time.

Any hints and suggestions are highly appreciated.


Thanks in advance,
Bernd

-- 
Bernd Schubert
Q-Leap Networks GmbH