From owner-freebsd-current@FreeBSD.ORG Tue Oct 12 21:48:07 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 19BA416A4CE for ; Tue, 12 Oct 2004 21:48:07 +0000 (GMT) Received: from pooker.samsco.org (pooker.samsco.org [168.103.85.57]) by mx1.FreeBSD.org (Postfix) with ESMTP id AB1AA43D3F for ; Tue, 12 Oct 2004 21:48:06 +0000 (GMT) (envelope-from scottl@freebsd.org) Received: from [192.168.254.11] (junior-wifi.samsco.home [192.168.254.11]) (authenticated bits=0) by pooker.samsco.org (8.12.11/8.12.10) with ESMTP id i9CLlYWZ011011; Tue, 12 Oct 2004 15:47:34 -0600 (MDT) (envelope-from scottl@freebsd.org) Message-ID: <416C50C8.9010903@freebsd.org> Date: Tue, 12 Oct 2004 15:46:48 -0600 From: Scott Long User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.7.2) Gecko/20040929 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Kris Kennaway References: <416AE7D7.3030502@murex.com> <200410112038.i9BKcCWt051290@apollo.backplane.com> <416C1B10.7030103@murex.com> <200410121818.i9CIIGRx092072@apollo.backplane.com> <20041012205105.GA76130@xor.obsecurity.org> In-Reply-To: <20041012205105.GA76130@xor.obsecurity.org> X-Enigmail-Version: 0.86.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, hits=0.0 required=3.8 tests=none autolearn=no version=2.63 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on pooker.samsco.org cc: Mikhail Teterin cc: freebsd-current@freebsd.org cc: bde@zeta.org.au Subject: Re: panic in ffs (Re: hangs in nbufkv) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Oct 2004 21:48:07 -0000 Kris Kennaway wrote: > On Tue, Oct 12, 2004 at 11:18:16AM -0700, Matthew Dillon wrote: > >>:[...] >>: >>:> But to be absolutely safe, I would follow Bruce's original suggestion >>:> and increase BKVASIZE to 64K, for your particular system. >>:> >>:> >>:After doing this and testing our backup script, the machine panicked two >>:hours later (about half-way through the backup) with >>:"initiate_write_inodeblock_ufs2: already started" (in >>:ufs/ffs/ffs_softdep.c)... I guess, block sizes above 16Kb are just buggy >>:and newfs(8) should be honest about it... >>: >>: -mi >> >> Well, it's possible that UFS has bugs related to large block sizes. >> People have gotten bitten on and off over the years but usually it >> works ok if you leave the 8:1 blocksize:fragsize ratio intact. e.g. >> if you have a 64KB block size then you should use a 8K frag size. >> If you have a 32KB block size then you should use a 4K frag size. >> >> I think the buffer cache itself is is likely not the source of this >> particular bug. > > > FYI, I ran the package build cluster with 4:1 ratios for a few months > and did not have problems. If there are major bugs there I would have > expected to come across them. > > Kris IIRC, the fragment allocation code in FFS allocates in terms of bits withing a byte, so anything that is 8:1 or less should work. Scott