From owner-freebsd-scsi@FreeBSD.ORG  Tue Sep 16 09:37:14 2014
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Date: Tue, 16 Sep 2014 17:36:48 +0800
From: Xu Zhe <xzpeter@gmail.com>
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To: freebsd-scsi@freebsd.org
Subject: How to disable hard disk write cache?
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Hi, all,

Does anyone knows how to disable write cache of hard disk?

I have found some hints here at Freebsd website:

https://www.freebsd.org/doc/handbook/configtuning-disk.html

However, this seems only work for ATA devices, what about SAS/NLSAS devices
(Meanwhile, it seems that there is no such sysctl in latest Freebsd release,
which is 10.0)?

Any hints are welcomed!

Thanks in advance.
Peter