From owner-freebsd-current Tue Mar 3 14:35:32 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA29480 for freebsd-current-outgoing; Tue, 3 Mar 1998 14:35:32 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from gate.lustig.com (gate.lustig.com [205.246.2.242]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id OAA29404 for ; Tue, 3 Mar 1998 14:35:14 -0800 (PST) (envelope-from barry@lustig.com) Received: (qmail 16771 invoked from network); 3 Mar 1998 22:27:39 -0000 Received: from devious.lustig.com (205.246.2.244) by gate.lustig.com with SMTP; 3 Mar 1998 22:27:39 -0000 Received: (qmail 1134 invoked by uid 21); 3 Mar 1998 22:27:50 -0000 Message-ID: <19980303222750.1133.qmail@devious.lustig.com> MIME-Version: 1.0 (NeXT Mail 4.2mach v148) Content-Type: text/enriched; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <34FC7EFC.237C228A@whistle.com> X-Nextstep-Mailer: Mail 4.2mach (Enhance 2.1) Received: by NeXT.Mailer (1.148.RR) From: Barry Lustig Date: Tue, 3 Mar 98 17:27:49 -0500 To: freebsd-current@FreeBSD.ORG Subject: Re: Panic with CURRENT & softupdates-240298 Reply-To: barry@lustig.com References: <34FC7EFC.237C228A@whistle.com> X-Organizations: Barry Lustig & Associates, Inc. Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Is anyone planning on back-porting soft-updates to 2.5.X? barry On Tue, 03 Mar 1998, Julian Elischer wrote: > Alok K. Dhir wrote: > > Mind explaining what soft-updates does? > > > > Soft Updates is a method of keeping track of teh dependencies > within the metadata of a filesystem, so that you can ensure > that at every stage, the on-disk image is consistent. It > includes such techniques as temporarily backing out certain > changes during disk writes, and queuing up a lot > of extra information. > > This seems a lot of work, however the gain is that: > 1/ after a crash fsck is not really required. > (except to recover blocks marked in use but really freed in > the last few seconds of running before the crash) > 2/ The writes are ALL (unles you do a fsync()) done async, > 3/ The dependencies automatically notice things like: > "I'm about to write a file but it's already been deleted" > and cancels the operation. > 4/ metadata operations such as deletion are grouped up and > done in bulk which is WAY faster. > > (that's just a quick start) > > julian > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-current" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message