From owner-cvs-src Tue Feb 11 6:34:20 2003 Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 92AD637B401; Tue, 11 Feb 2003 06:34:18 -0800 (PST) Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id AB33E43FA3; Tue, 11 Feb 2003 06:34:17 -0800 (PST) (envelope-from robert@fledge.watson.org) Received: from fledge.watson.org (fledge.pr.watson.org [192.0.2.3]) by fledge.watson.org (8.12.6/8.12.5) with SMTP id h1BEY7P4021986; Tue, 11 Feb 2003 09:34:07 -0500 (EST) (envelope-from robert@fledge.watson.org) Date: Tue, 11 Feb 2003 09:34:06 -0500 (EST) From: Robert Watson X-Sender: robert@fledge.watson.org To: Juli Mallett Cc: Peter Wemm , src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sbin/newfs Makefile mkfs.c newfs.c newfs.h ref.test In-Reply-To: <20030210220423.A36674@FreeBSD.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-cvs-src@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Mon, 10 Feb 2003, Juli Mallett wrote: > > Umm, I object! This is a massive performance loss on disks without track > > write buffering (eg: many raid systems).. While it isn't so bad for ufs2 > > newfs, it is a Big Deal for ufs1 for interchangeability. > > OK. I was kind of hoping to put a general write cache (and since we do > reads, a general buffer cache, in a sense) into libufs, but I suppose I > could just put back the wc stuff, and avoid calling into libufs for > anything other than bread/bwrite. > > Which would you prefer? Do you know of anything other than newfs where > it matters? If you're going to use a write cache with fsck, you need to be Really Really Careful. The last thing we want is a power-down during fsck to completely hose the system because it violates write-order constraints. Hopefully fsck isn't in the business of producing such things, but caution should be applied. Robert N M Watson FreeBSD Core Team, TrustedBSD Projects robert@fledge.watson.org Network Associates Laboratories To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-src" in the body of the message