Date: Thu, 17 Jun 1999 20:53:20 +0200 (CEST) From: Wilko Bulte <wilko@yedi.iaf.nl> To: chad@DCFinc.com Cc: jedgar@fxp.org, mike@smith.net.au, sec@42.org, des@flood.ping.uio.no, freebsd-stable@FreeBSD.ORG Subject: Re: / not properly unmounted ? Message-ID: <199906171853.UAA01003@yedi.iaf.nl> In-Reply-To: <199906171637.JAA29029@freeway.dcfinc.com> from "Chad R. Larson" at "Jun 17, 1999 9:37:58 am"
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As Chad R. Larson wrote ... > > On Thu, 17 Jun 1999, Mike Smith wrote: > >>> I added a sysctl variable (machdep.powerdown_delay) to allow the > >>> disk cache to flush by itself before APM powering the system off. > >>> After applying the attached patch (tested on 3.2-STABLE) and > >>> installing a new kernel, just use 'sysctl -w > >>> machdep.powerdown_delay=5' for a 5 second delay. > >>> > >>> I don't know if this is appropriate for actual inclusion into the > >>> kernel...if so, I can see about merging it into -CURRENT and/or > >>> changing to a more appropriate sysctl level (i.e. kern, hw). > >> > >> dingo:~>sysctl -a |grep delay > >> kern.shutdown.poweroff_delay: 0 > >> ... > >> > > Guys, this seems like the wrong solution to the original problem. > > 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? The kernel can generally only check if *itself* has dirty buffers. Does not help if a cache *on the disk* sits on unflushed data that goes down the tubes when the power goes away. On SCSI you can send a SYNCHRONISE CACHE command, which *should* work (but does not always according to my info). -- | / 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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