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Date: Thu, 7 Apr 2011 21:25:40 +0000
From: Alexander Best <arundel@freebsd.org>
To: Garrett Cooper <yanegomi@gmail.com>
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Cc: svn-src-head@freebsd.org, Alexander Motin <mav@freebsd.org>,
	src-committers@freebsd.org, svn-src-all@freebsd.org
Subject: Re: svn commit: r220412 - in head: share/man/man4 sys/cam/ata
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On Thu Apr  7 11, Garrett Cooper wrote:
> On Thu, Apr 7, 2011 at 12:03 PM, Alexander Best <arundel@freebsd.org> wrote:
> > On Thu Apr  7 11, Alexander Motin wrote:
> >> Author: mav
> >> Date: Thu Apr  7 08:17:53 2011
> >> New Revision: 220412
> >> URL: http://svn.freebsd.org/changeset/base/220412
> >>
> >> Log:
> >>   Make ada(4) driver to control device write cache, same as ata(4) does.
> >>   Add kern.cam.ada.write_cache sysctl/tunable to control it alike hw.ata.wc.
> >
> > how hard would it be to support per device sysctls/tunables? i'd really like to
> > do:
> >
> > kern.cam.ada.0.write_cache=0 (root fs)
> > kern.cam.ada.1.write_cache=1 (/usr, /var, etc.)
> 
> Does it really make sense to turn on write caching for one drive and
> not the other(s)?

i think so. for "/" i want maximum safebelts. so i'd like to disable the write
cache and mount it with the "sync" option. for /usr/ and all the other mount
points i'd like maximum speed with write caching enabled and mounted with the
"noasync" and "noatime" options.

cheers.
alex

> Thanks,
> -Garrett

-- 
a13x