From owner-freebsd-arch Tue Dec 11 14:40:52 2001 Delivered-To: freebsd-arch@freebsd.org Received: from rover.village.org (rover.bsdimp.com [204.144.255.66]) by hub.freebsd.org (Postfix) with ESMTP id 860CC37B419; Tue, 11 Dec 2001 14:40:40 -0800 (PST) Received: from harmony.village.org (harmony.village.org [10.0.0.6]) by rover.village.org (8.11.3/8.11.3) with ESMTP id fBBMeca82591; Tue, 11 Dec 2001 15:40:38 -0700 (MST) (envelope-from imp@harmony.village.org) Received: from harmony.village.org (localhost [127.0.0.1]) by harmony.village.org (8.11.6/8.11.6) with ESMTP id fBBMebM31038; Tue, 11 Dec 2001 15:40:37 -0700 (MST) (envelope-from imp@harmony.village.org) Message-Id: <200112112240.fBBMebM31038@harmony.village.org> To: Greg Lehey Subject: Re: Getting rid of /usr file system (was: Using a larger block size on large filesystems) Cc: Terry Lambert , Nik Clayton , Mike Smith , arch@FreeBSD.org, Marko Zec , "Louis A. Mamakos" , Matthew Dillon , Sheldon Hearn , freebsd-arch@FreeBSD.org In-reply-to: Your message of "Wed, 12 Dec 2001 09:06:10 +1030." <20011212090610.D67986@monorchid.lemis.com> References: <20011212090610.D67986@monorchid.lemis.com> <20011210124458.B63585@monorchid.lemis.com> <20011208102658.B11428@dragon.nuxi.com> <200112082050.fB8Ko1T01347@mass.dis.org> <20011209164606.C83634@monorchid.lemis.com> <20011209104437.A69671@clan.nothing-going-on.org> <3C141A26.9D8BC688@mindspring.com> <200112110946.fBB9kMM26143@harmony.village.org> Date: Tue, 11 Dec 2001 15:40:37 -0700 From: Warner Losh Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message <20011212090610.D67986@monorchid.lemis.com> Greg Lehey writes: : On Tuesday, 11 December 2001 at 2:46:22 -0700, Warner Losh wrote: : > In message <20011210124458.B63585@monorchid.lemis.com> Greg Lehey writes: : > : Well, I'm not forgetting this, I didn't know it. But it seems to make : > : sense. This was one of the things I mentioned earlier. : > : > I have had systems that have separate / and /usr, and others that have : > one big /. I don't mind so much that / and /usr are on the same : > partition by default, but I don't want to see us go to one big '/'. : > That does cause more problems than it solves (and makes it impossible : > to do fastish boots by kicking the fsck into the back ground). : > However, I've had occasion to have systems where / and /usr need to be : > separate partitions, so as long as we don't require them to be on the : > same partition, I'd say go for it. : > : > I suspect, however, that we'll find that crash recovery really is a : > big factor since /usr does get written to on every man command that : > generates a new man page... : : That's pretty seldom. : : $ find /usr/share/man/cat* -type f | wc -l : 3277 : $uname -v : FreeBSD 5.0-CURRENT #0: Sat Sep 30 17:31:17 CST 2000 grog@wantadilla.lemis.com:/src/FreeBSD/WANTADILLA/src/sys/compile/WANTADILLA : : That's about 7.5 man pages per day. This is on my main machine, and I : suspect I use man pages more than most. : : More to the point, how many broken /usr file systems have you *ever* : had with FreeBSD? Maybe 5. I've rarely had one when / wasn't also broken. :-) However, the argument for /usr is more than just that it is for crash recovery. I'd have fewer if /usr was mounted read only (which it can't be for the man page issue, and other problems). We mount / read only on our embedded systems and combine / and /usr onto one partition and like everything dynamic. We also mount /var on MFS and have a read/write /mod for things that change (but that can be recovered by some means, should we need to newfs things). The argument is that if / is small, the chances of it being corrupt are smaller and the risk is lower of using it as an unchecked file system. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message