From owner-freebsd-arch Thu Mar 29 20:12: 6 2001 Delivered-To: freebsd-arch@freebsd.org Received: from fw.wintelcom.net (ns1.wintelcom.net [209.1.153.20]) by hub.freebsd.org (Postfix) with ESMTP id 8C2EC37B71E for ; Thu, 29 Mar 2001 20:12:03 -0800 (PST) (envelope-from bright@fw.wintelcom.net) Received: (from bright@localhost) by fw.wintelcom.net (8.10.0/8.10.0) id f2U4Buc08081; Thu, 29 Mar 2001 20:11:56 -0800 (PST) Date: Thu, 29 Mar 2001 20:11:56 -0800 From: Alfred Perlstein To: "Michael C . Wu" Cc: Bakul Shah , Kirk McKusick , arch@FreeBSD.ORG Subject: Re: Background Fsck Message-ID: <20010329201156.P9431@fw.wintelcom.net> References: <200103290522.VAA06966@beastie.mckusick.com> <200103300053.TAA27553@thunderer.cnchost.com> <20010329220128.B21838@peorth.iteration.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010329220128.B21838@peorth.iteration.net>; from keichii@iteration.net on Thu, Mar 29, 2001 at 10:01:28PM -0600 X-all-your-base: are belong to us. Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG * Michael C . Wu [010329 20:01] wrote: > I think Kirk would know a thing or two about FFS. ;-) > > On Thu, Mar 29, 2001 at 04:53:55PM -0800, Bakul Shah scribbled: > | Dumb question time. Why would I want to run a background > | fsck on an active filesystem? One wouldn't mount an unsafe > > You want your system to be up as soon as possible. > Have you ever tried to fsck even just a 200gb system? > > | filesystem in the first place. Perhaps you are talking about > | background garbage collection on an active fs -- blocks and > > No, he calls it background fsck because that is what it is. > > | inodes not reachable from the root set of objects (root inode > | + freelist + superblock?) recovered lazily. If this is > | really what you have, wouldn't it make sense to call it > | something else (e.g. fsgc)? > > Please at least try to understand what this feature is and does. > > | On a somewhat related note, I have always wondered if the > | current fsck algorithm can be significantly improved or if it > | is about as efficient as it can be (barring any peephole code > | improvements). > > This is a significant architecture addition/redesign to > reduce fsck time. er, actually Bakul Shah is correct in his questions, you're the one who doesn't seem to understand. :) It is basically a garbage collection that's possible because the disk is "frozen" in the snapshot. As far as speeding up fsck in general, I haven't heard anything, suggestions are welcome. :) And as far as 'fsgc', that might be a good thing to call it, basically put code into 'fsck' so that when argv[0] = "fscg" it does the snapshotting and gc sweep. -- -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] Instead of asking why a piece of software is using "1970s technology," start asking why software is ignoring 30 years of accumulated wisdom. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message