Dell PERC5/i SAS5/5IR - RAID monitoring
mail at michaelworobcuk.de
Fri Jul 20 20:08:24 UTC 2007
> Tom Judge wrote:
> As for performance issues with the SAS5/i, there is a problem in
> the controller. A work arround was created by Scott Long which
> created a sysctl that could be set to cause the controller to turn
> on the on drive write cache's. These changes where commited to
> RELENG_6 on 2007-06-05 21:32:57 UTC.
>> Here is the original commit log:
>> scottl 2007-06-03 23:13:05 UTC
>> FreeBSD src repository
>> Modified files:
>> sys/dev/mpt mpt.c mpt.h mpt_cam.c
>> Add support for reading extended configuration pages.
>> Do a top level topology scan on the SAS controller. If
>> any SATA device are discovered in this scan, send a passthrough
>> FIS to set the write cache. This is controllable through the
>> following tunable at boot:
>> -1 = Do not configure, use the controller default
>> 0 = Disable the write cache
>> 1 = Enable the write cache
>> The default is -1. This tunable is just a hack and may be
>> deprecated in the future.
I set mpt.enable_sata_wc to 1, as hw.mpt.enable_sata_wc is, AFAIK not
tunable in mpt_cam.c. This did not take any effect to the
performance. Is there anything else to change ?
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