Date: Thu, 17 Jun 1999 20:50:40 +0200 (CEST) From: Wilko Bulte <wilko@yedi.iaf.nl> To: bright@rush.net (Alfred Perlstein) Cc: chad@DCFinc.com, mike@smith.net.au, jedgar@fxp.org, sec@42.org, des@flood.ping.uio.no, freebsd-stable@FreeBSD.ORG Subject: Re: / not properly unmounted ? Message-ID: <199906171850.UAA00996@yedi.iaf.nl> In-Reply-To: <Pine.BSF.3.96.990617120558.14320m-100000@cygnus.rush.net> from Alfred Perlstein at "Jun 17, 1999 12: 7: 7 pm"
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As Alfred Perlstein wrote ... > On Thu, 17 Jun 1999, Chad R. Larson wrote: > > > As I recall, Mike Smith wrote: > > > > The first complaint was that the power-down was catching disk stuff > > > > still in cache. Setting an arbitrary delay on the way down seems > > > > inefficient at best, and possibly not sufficient. How about instead > > > > just making sure all buffers are flushed before the power-down is > > > > allowed to to occur, however long that takes? > > > > > > You can't do this, because it's the _disk_ that holds the cached data. > > > > Ok, I missed something in the original post? He's using some kind > > of caching (or RAID) controller? > > > > no, some drives have write caching, if you suddenly cut power, they > don't have enough charge left to write out the data in the cache. Volatile(*) writeback caches are a Bad Thing(tm). It escapes me why people can't get that message into their skulls. Sigh.. (*) volatile as in "not powerfailure protected. -- | / o / / _ Arnhem, The Netherlands - Powered by FreeBSD - |/|/ / / /( (_) Bulte WWW : http://www.tcja.nl http://www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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