X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (av.hub.org [200.46.204.144]) by postgresql.org (Postfix) with ESMTP id B8C149DCA8C for ; Tue, 21 Mar 2006 08:48:45 -0400 (AST) Received: from postgresql.org ([200.46.204.71]) by localhost (av.hub.org [200.46.204.144]) (amavisd-new, port 10024) with ESMTP id 63465-04 for ; Tue, 21 Mar 2006 08:48:48 -0400 (AST) X-Greylist: from auto-whitelisted by SQLgrey- Received: from vms042pub.verizon.net (vms042pub.verizon.net [206.46.252.42]) by postgresql.org (Postfix) with ESMTP id 8EBAA9DC9B2 for ; Tue, 21 Mar 2006 08:48:43 -0400 (AST) Received: from osgiliath.mathom.us ([151.200.254.241]) by vms042.mailsrvcs.net (Sun Java System Messaging Server 6.2-4.02 (built Sep 9 2005)) with ESMTPA id <0IWH00F5GA9AHHJ4@vms042.mailsrvcs.net> for pgsql-performance@postgresql.org; Tue, 21 Mar 2006 06:48:47 -0600 (CST) Received: from localhost (localhost [127.0.0.1]) by osgiliath.mathom.us (Postfix) with ESMTP id 6A6366E46D for ; Tue, 21 Mar 2006 07:48:45 -0500 (EST) Received: from osgiliath.mathom.us ([127.0.0.1]) by localhost (osgiliath.home.mathom.us [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 30125-03 for ; Tue, 21 Mar 2006 07:48:44 -0500 (EST) Received: by osgiliath.mathom.us (Postfix, from userid 1000) id DA89F6E775; Tue, 21 Mar 2006 07:48:43 -0500 (EST) Date: Tue, 21 Mar 2006 07:48:43 -0500 From: Michael Stone Subject: Re: Migration study, step 1: bulk write performance In-reply-to: <20060321120158.GO15742@pervasive.com> To: pgsql-performance@postgresql.org Mail-followup-to: pgsql-performance@postgresql.org Message-id: <20060321124841.GZ15140@mathom.us> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii; format=flowed Content-disposition: inline X-Pgp-Fingerprint: 53 FF 38 00 E7 DD 0A 9C 84 52 84 C5 EE DF 7C 88 X-Virus-Scanned: Debian amavisd-new at mathom.us References: <7F10D26ECFA1FB458B89C5B4B0D72C2B088286@sesrv12.wirelesscar.com> <1142867952.16487.96.camel@coppola.muc.ecircle.de> <20060321112759.GF15742@pervasive.com> <1142941966.23597.4.camel@coppola.muc.ecircle.de> <20060321115618.GA12880@uio.no> <20060321120158.GO15742@pervasive.com> User-Agent: Mutt/1.5.11+cvs20060126 X-Virus-Scanned: by amavisd-new at hub.org X-Spam-Status: No, score=1.047 required=5 tests=[AWL=-0.189, RCVD_IN_SORBS_WEB=1.236] X-Spam-Score: 1.047 X-Spam-Level: * X-Archive-Number: 200603/398 X-Sequence-Number: 17835 On Tue, Mar 21, 2006 at 06:01:58AM -0600, Jim C. Nasby wrote: >On Tue, Mar 21, 2006 at 12:56:18PM +0100, Steinar H. Gunderson wrote: >> For the record, that's the wrong way round. For the data partitioning >> metadata journaling is enough, and for the WAL partition you don't need any >> FS journaling at all. > >Are you sure? Yes. :) You actually shouldn't need metadata journaling in either case--fsck will do the same thing. But fsck can take a *very* long time on a large paritition, so for your data partition the journaling fs is a big win. But your wal partition isn't likely to have very many files and should fsck in a snap, and data consistency is taken care of by synchronous operations. (Which is the reason you really don't need/want data journalling.) Mike Stone