Date: Sat, 27 Sep 2008 17:36:17 +1000 From: Peter Jeremy <peterjeremy@optushome.com.au> To: Jeremy Chadwick <koitsu@freebsd.org> Cc: Derek Kuli??ski <takeda@takeda.tk>, freebsd-stable@freebsd.org, Clint Olsen <clint.olsen@gmail.com> Subject: Re: UNEXPECTED SOFT UPDATE INCONSISTENCY; RUN fsck MANUALLY Message-ID: <20080927073616.GP15376@server.vk2pj.dyndns.org> In-Reply-To: <20080927064417.GA43638@icarus.home.lan> References: <20080921213426.GA13923@0lsen.net> <20080921215203.GC9494@icarus.home.lan> <20080921215930.GA25826@0lsen.net> <20080921220720.GA9847@icarus.home.lan> <249873145.20080926213341@takeda.tk> <20080927051413.GA42700@icarus.home.lan> <765067435.20080926223557@takeda.tk> <20080927064417.GA43638@icarus.home.lan>
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--InRyi6yyXSYzKD4c Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2008-Sep-26 23:44:17 -0700, Jeremy Chadwick <koitsu@freebsd.org> wrote: >On Fri, Sep 26, 2008 at 10:35:57PM -0700, Derek Kuli??ski wrote: >> As far as I know (at least ideally, when write caching is disabled) =2E.. >FreeBSD atacontrol does not let you toggle such features (although "cap" >will show you if feature is available and if it's enabled or not). True but it can be disabled via the loader tunable hw.ata.wc (at least in theory - apparently some drives don't obey the cache disable command to make them look better in benchmarks). >Users using SCSI will most definitely have the ability to disable >said feature (either via SCSI BIOS or via camcontrol). Soft-updates plus write caching isn't an issue with tagged queueing (which is standard for SCSI) because the critical point for soft-updates is knowing when the data is written to non-volatile storage - which tagged queuing provides. --=20 Peter Jeremy Please excuse any delays as the result of my ISP's inability to implement an MTA that is either RFC2821-compliant or matches their claimed behaviour. --InRyi6yyXSYzKD4c Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkjd4nAACgkQ/opHv/APuIfu8ACgiVxzBQXk8Nv7v3n9qQ70Ht1k 9q0AmgMzIKxTvks9+CXUyGENwP7FJTN7 =y0+F -----END PGP SIGNATURE----- --InRyi6yyXSYzKD4c--
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