Date: Sun, 31 Jan 2010 21:59:37 +0100 (CET) From: Alexander Best <alexbestms@wwu.de> To: Warren Block <wblock@wonkity.com>, Jung-uk Kim <jkim@FreeBSD.org> Cc: freebsd-hackers@FreeBSD.org Subject: Re: Spin down HDD after disk sync or before power off Message-ID: <permail-20100131205937f0889e84000009fa-a_best01@message-id.uni-muenster.de> In-Reply-To: <alpine.BSF.2.00.1001291745150.47497@wonkity.com>
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imo this patch takes good care of the problem. would be nice to have it in HEAD. cheers. alex Warren Block schrieb am 2010-01-30: > On Fri, 29 Jan 2010, Jung-uk Kim wrote: > >On Friday 29 January 2010 05:38 pm, Warren Block wrote: > >I am not 100% sure but I think it should be something like the > >attached patch. > Yes, I had the two commands backwards. So let me try to summarize: > ad_shutdown uses ATA_FLUSHCACHE writes out any cached data, but does > not park the heads. At powerdown, the heads do an emergency park, > which is louder than a normal park and possibly damaging. > Adding ATA_STANDBY_IMMEDIATE after the ATA_FLUSHCACHE will park the > heads more quietly and possibly more safely. Should do no harm, at > least. > ad_spindown looks like it's meant to spin the disk down for sleep > operations, and does some higher-level things. > I suspect flushcache and standby should be as close together as > possible to avoid the chance of anything getting back into the cache > or spinning the disk back up. > Anyway, testing this use of ad_spindown inside ad_shutdown brought > back the GLINK on shutdown. > A fixed version of the earlier patch that does flushcache and then > standbyimmediate is attached. > -Warren Block * Rapid City, South Dakota USA
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