Date: Wed, 30 Jan 2002 11:31:45 -0800 From: "Kevin Oberman" <oberman@es.net> To: "Brian T. Schellenberger" <bts@babbleon.org> Cc: Varshavchick Alexander <alex@metrocom.ru>, questions@FreeBSD.ORG Subject: Re: Again Softupdates on 4.5 Message-ID: <20020130193145.5ED395D0B@ptavv.es.net> In-Reply-To: Your message of "Wed, 30 Jan 2002 14:17:27 EST." <20020130191727.017CE4078@i8k.babbleon.org>
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> From: Brian T.Schellenberger <bts@babbleon.org> > Date: Wed, 30 Jan 2002 14:17:27 -0500 > > On Wednesday 30 January 2002 12:53 pm, Kevin Oberman wrote: > > > Date: Wed, 30 Jan 2002 20:09:14 +0300 (MSK) > > > From: Varshavchick Alexander <alex@metrocom.ru> > > > Sender: owner-freebsd-questions@FreeBSD.ORG > > > > > > Then the difference lays only in the fact that on 4.5 the softupdates > > > flag can be turned on in the sysinstall procedure? > > > > No. I means that sysinstall turns on softupdates for all non-root, > > non-swap partitions by default. Under 4.4 you had to tell sysinstall > > that you wanted softupdates (with the 'S' command). There is no change > > to the functionality in 4.5, only to the default operation. > > Does 4.5 also leave write-caching on by default? If so, I think that's a > terrible mistake. Would I be correct in assuming it's way to late to get > this reconsidered? Yes, write-cache is enabled by default on 4.5 (as it was on 4.4). The debate on this has been long and often mis-informed. There is a real risk of metadata corruption with write caching and softupdates, but it appears to be EXTREMELY small. So far no case of it has actually been confirmed. There is a significant chance of data loss in recently updated files with write-cache, but that is also true without softupdates. The only totally safe way to deal with this is to run fully synchronous with write-cache disabled. As I understand it the conclusion of the core team was that softupdates advantages more than justified the risks. 4.5 has been released. I already have burned CDs. I think it's too late. > (And what list ought I have been reading to have known about these plans?) hackers and stable. R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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