From owner-freebsd-questions Mon Apr 20 00:01:41 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id AAA19769 for freebsd-questions-outgoing; Mon, 20 Apr 1998 00:01:41 -0700 (PDT) (envelope-from owner-freebsd-questions@FreeBSD.ORG) Received: from caladan.tdx.co.uk (caladan.tdx.co.uk [195.188.177.4]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id HAA19758 for ; Mon, 20 Apr 1998 07:01:35 GMT (envelope-from kpielorz@tdx.co.uk) Received: from tdx.co.uk (lorca-tx.tdx.co.uk [195.188.177.242]) by caladan.tdx.co.uk (8.8.8/8.8.8) with ESMTP id IAA01535; Mon, 20 Apr 1998 08:01:28 +0100 (BST) (envelope-from kpielorz@tdx.co.uk) Message-ID: <353AF2B2.3D7432DD@tdx.co.uk> Date: Mon, 20 Apr 1998 08:01:06 +0100 From: Karl Pielorz Organization: TDX X-Mailer: Mozilla 4.04 [en] (WinNT; I) MIME-Version: 1.0 To: Richard Puga CC: freebsd-questions@FreeBSD.ORG Subject: Re: ccd device References: <199804201330.DAA07776@mauibuilt.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Hi, I don't beleive it's possible to change the interleave without backing off the data from the ccd and re-formatting it... :-( As for the 'correct' interleave to use - your probably better off say starting with a value of 128, try a few performance tests - then try an interleave of say 256, or 64 etc. - and just keep going for a while... It is extreemly hard (i.e. I beleive almost impossible) to mathematically calculate the 'optimum' interleave - and this varies with the type of disk access as well, so what's good for reading small files - isn't so hot for writing large files etc. :-( I have 2 CCD's on my system, I tend to find SCSI goes quicker with larger interleaves than IDE - having said that both mine are set to an interleave of 32 at the moment, after I just finished rebuilding my system... Regards, Karl Pielorz Richard Puga wrote: > > Quick question.. > > can you resize the interleave on a ccd device without re-newfs-ing it and > re-installing software?? > > also if anyone has a suggestion as to what to set the interleave at for > a system using 5, 4.1Gig Wide Segate hawks at 5700RPM.. im striping them > and looking for overall prefomance in a system which isn't a news server..:) > > Thanks in advance... > > RP > puga@mauibuilt.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message