From owner-freebsd-hackers Wed Oct 21 16:37:26 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id QAA28782 for freebsd-hackers-outgoing; Wed, 21 Oct 1998 16:37:26 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from alcanet.com.au (border.alcanet.com.au [203.62.196.10]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id QAA28777 for ; Wed, 21 Oct 1998 16:37:23 -0700 (PDT) (envelope-from peter.jeremy@auss2.alcatel.com.au) Received: by border.alcanet.com.au id <40343>; Thu, 22 Oct 1998 09:36:07 +1000 Date: Thu, 22 Oct 1998 09:36:35 +1000 From: Peter Jeremy Subject: FS Behaviour with small frags To: hackers@FreeBSD.ORG Message-Id: <98Oct22.093607est.40343@border.alcanet.com.au> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I'm looking at using a 4096/512 filesystem (instead of the standard 8192/1024) for news spool. (Based on an analysis of my current news spool, this will save about 10% of the space). Are there any down-sides to using 4096/512 instead of 8192/1024? For the same disk and cylinder group organisation, will a 4096/512 FS be slower or use more system resources than an 8192/1024 FS (given lots of small files)? My major concerns are that either the buffer cache will allocate 8K buffers and not use half of them (effectively halving the cache size), or that allocating a mixture of 4K and 8K buffers will lead to excessive fragmentation (reducing the performance of the remaining 8K FS). Peter -- Peter Jeremy (VK2PJ) peter.jeremy@alcatel.com.au Alcatel Australia Limited 41 Mandible St Phone: +61 2 9690 5019 ALEXANDRIA NSW 2015 Fax: +61 2 9690 5247 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message