From owner-freebsd-hackers Wed Aug 27 12:05:35 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id MAA28234 for hackers-outgoing; Wed, 27 Aug 1997 12:05:35 -0700 (PDT) Received: from iafnl.es.iaf.nl (uucp@iafnl.es.iaf.nl [195.108.17.20]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id MAA28214 for ; Wed, 27 Aug 1997 12:05:26 -0700 (PDT) Received: by iafnl.es.iaf.nl with UUCP id AA08810 (5.67b/IDA-1.5 for freebsd-hackers@FreeBSD.ORG); Wed, 27 Aug 1997 21:05:31 +0200 Received: (from wilko@localhost) by yedi.iaf.nl (8.8.5/8.6.12) id UAA01011; Wed, 27 Aug 1997 20:45:13 +0200 (MET DST) From: Wilko Bulte Message-Id: <199708271845.UAA01011@yedi.iaf.nl> Subject: Re: ? power outages and file system corruption To: terry@lambert.org (Terry Lambert) Date: Wed, 27 Aug 1997 20:45:13 +0200 (MET DST) Cc: Shimon@i-Connect.Net, burt@focusplus.com, freebsd-hackers@FreeBSD.ORG In-Reply-To: <199708262303.QAA04296@phaeton.artisoft.com> from "Terry Lambert" at Aug 26, 97 04:03:37 pm X-Organisation: Private FreeBSD site - Arnhem, The Netherlands X-Pgp-Info: PGP public key at 'finger wilko@freefall.freebsd.org' X-Mailer: ELM [version 2.4 PL24 ME8a] Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk As Terry Lambert wrote... > > > > In theory, a journaling filesystem will do that. Veritas is a good name > > for these. The problem with most of these is that a $300 UPS is cheaper > > and more reliable. Most such filesystems are attached to such an increase > > in complexity that the most common cause of curruption is a filesystem code > > bug. Even a UPS does not help you then. > > A journalling filesystem is just another way to protect FS metadata > integrity without doing a traditional fsck (an abbreviated fsck > using the journalling data occurs as part of mount). > > A journalling FS does not guarantee against FS corruption. It only > guarantees against structure corruption. FS data corrpution can Right. Now an exercise: find a salesdroid who knows that ;-) Another advantage apart for the very time consuming fsck is that fsck tends to allocate huge amounts of memory in case of large FS checks. We observed something like 500Mb swap consumed by Solaris/Sparc fsck on a 120Gb FS. Really enjoyable that after a power fail or something you find that your system won't boot because fsck cannot do it's job for lack of memory. Wilko _ ____________________________________________________________________ | / o / / _ Bulte email: wilko@yedi.iaf.nl http://www.tcja.nl/~wilko |/|/ / / /( (_) Arnhem, The Netherlands - Do, or do not. There is no 'try' ----------------------------------------------------------------------Yoda