From owner-freebsd-current Wed Oct 6 16:16:20 1999 Delivered-To: freebsd-current@freebsd.org Received: from shell.futuresouth.com (shell.futuresouth.com [198.78.58.28]) by hub.freebsd.org (Postfix) with ESMTP id 2229F14EA4 for ; Wed, 6 Oct 1999 16:16:10 -0700 (PDT) (envelope-from fullermd@futuresouth.com) Received: (from fullermd@localhost) by shell.futuresouth.com (8.9.3/8.9.3) id SAA29629; Wed, 6 Oct 1999 18:15:43 -0500 (CDT) Date: Wed, 6 Oct 1999 18:15:42 -0500 From: "Matthew D. Fuller" To: Peter Jeremy Cc: freebsd-current@FreeBSD.ORG Subject: {a}sync updates (was Re: make install trick) Message-ID: <19991006181542.S20768@futuresouth.com> References: <99Oct6.103524est.40351@border.alcanet.com.au> <99Oct6.145359est.40347@border.alcanet.com.au> <19991006154419.O20768@futuresouth.com> <99Oct7.085536est.40332@border.alcanet.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0pre3i In-Reply-To: <99Oct7.085536est.40332@border.alcanet.com.au> X-OS: FreeBSD Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Thank you, this is *EXACTLY* what I was looking for :) On Thu, Oct 07, 1999 at 08:59:00AM +1000, a little birdie told me that Peter Jeremy remarked > > As far as I can tell, the net effect is that inode access time updates > will remain async writes into the filesystem. > > An easy way to tell would be to use NOATIME and see if you're still > getting async writes. (Or any writes at all). This does appear to be it. Testing such things as (cat /kernel >> /dev/null && sync && sync) preceded and followed by a 'mount' call in another window does show the 'async' counter incrementing, and when I remount it noatime it no longer does. Is this good, bad, ugly, or just inconsistent? On the one hand, you can argue that 'sync should be sync should be sync, I don't bloody care, just don't do anything async at all', since that's what it's supposed to do: mount(8): sync All I/O to the file system should be done synchronously. On the gripping hand, you can say, 'this is an ATIME update, there's no way its presence or lack thereof can do anything bad to the filesystem, so let it be async since it takes extra work to make it sync'. Does anyone have any feeling either way on this? I, unfortunately, seem to have strong feelings BOTH ways... sync atime updates will slow it down, but on the flip side, if you're mounting sync in the first place you don't care much for speed anyway. Thoughts? -- Matthew Fuller (MF4839) | fullermd@over-yonder.net Unix Systems Administrator | fullermd@futuresouth.com Specializing in FreeBSD | http://www.over-yonder.net/ FutureSouth Communications | ISPHelp ISP Consulting "The only reason I'm burning my candle at both ends, is because I haven't figured out how to light the middle yet" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message