Date: Sat, 19 Apr 2008 23:33:44 +0200 From: Tore Lund <tl32@next.online.no> To: freebsd-questions@freebsd.org Subject: Re: Sidetracked: why gjournal over soft-updates (Was: Re: UFS2 Message-ID: <480A6538.5000102@next.online.no> In-Reply-To: <9bbcef730804191302t31eaf472s1b7e64fe5915b9b1@mail.gmail.com> References: <fu5nkb$3ib$1@ger.gmane.org> <790871.1688.qm@web57004.mail.re3.yahoo.com> <9bbcef730804180840y77adff73x7ad0cf90c82633a9@mail.gmail.com> <200804192005.06962.fbsd.questions@rachie.is-a-geek.net> <9bbcef730804191302t31eaf472s1b7e64fe5915b9b1@mail.gmail.com>
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Ivan Voras wrote:
> 1) Soft-updates were created in a different time, with different
> requirements than modern hard drives (especially desktop hard drives)
> can deliver. Especially, SU requires that data it once sends to the
> drive gets written immediately, not cached by the drive. Modern
> desktop drives don't do that so journaling is today actually safer
> than SU
The caching can be stopped by putting "hw.ata.wc=0" into
/boot/loader.conf. Doesn't that settle this point about safety?
> For details, you can search the mailing list archives - what I've said
> is nothing original and the topic has been talked about a lot.
Since we use softupdates and others use gjournal, one suspects that
there are reasons why "real" journaling systems have not been adopted.
Once the subject has been raised, it would be nice to get an up-to-date
view from someone in the know - as opposed to having to leaf through
hundreds of old threads on the topic. TIA.
--
Tore
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