From owner-freebsd-questions@FreeBSD.ORG Sat Nov 17 21:08:25 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 21320151 for ; Sat, 17 Nov 2012 21:08:25 +0000 (UTC) (envelope-from wblock@wonkity.com) Received: from wonkity.com (wonkity.com [67.158.26.137]) by mx1.freebsd.org (Postfix) with ESMTP id AD17E8FC08 for ; Sat, 17 Nov 2012 21:08:24 +0000 (UTC) Received: from wonkity.com (localhost [127.0.0.1]) by wonkity.com (8.14.5/8.14.5) with ESMTP id qAHL8GAf009556; Sat, 17 Nov 2012 14:08:16 -0700 (MST) (envelope-from wblock@wonkity.com) Received: from localhost (wblock@localhost) by wonkity.com (8.14.5/8.14.5/Submit) with ESMTP id qAHL8FYf009553; Sat, 17 Nov 2012 14:08:16 -0700 (MST) (envelope-from wblock@wonkity.com) Date: Sat, 17 Nov 2012 14:08:15 -0700 (MST) From: Warren Block To: Gary Aitken Subject: Re: 9.0 crash, ssd or filesystem problem? In-Reply-To: <50A7EE9B.4070003@dreamchaser.org> Message-ID: References: <50A53FF1.7050806@dreamchaser.org> <50A602AB.2060307@dreamchaser.org> <50A66659.5040406@dreamchaser.org> <50A6FFC0.3050902@dreamchaser.org> <50A7EE9B.4070003@dreamchaser.org> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (wonkity.com [127.0.0.1]); Sat, 17 Nov 2012 14:08:16 -0700 (MST) Cc: FreeBSD Mailing List X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Nov 2012 21:08:25 -0000 On Sat, 17 Nov 2012, Gary Aitken wrote: > On 11/16/12 21:38, Warren Block wrote: >> On Fri, 16 Nov 2012, Gary Aitken wrote: >> >>> On 11/16/12 12:10, Warren Block wrote: >>> >>>> Additional SSD suggestions: when creating partitions, leave out the swap >>>> partition. If you have lots of memory, leave out the /tmp partition. Add >>>> that extra space to the /usr partition. >>>> >>>> Format the UFS filesystems with -Ut, for soft updates and TRIM support. >>>> (Make sure your SSD supports TRIM, almost all do.) (I don't use soft >>>> updates journaling.) >>>> >>>> Use dd(1) to make a zero-filled file on /usr somewhere, say /usr/swap. >>>> Make it the size you want swap to be, and do not make it a sparse file. >>>> Tell the system to use the swapfile in /etc/rc.conf: >>>> >>>> swapfile="/usr/swap" >>>> >>>> Use tmpfs for /tmp in /etc/fstab: >>>> >>>> tmpfs /tmp tmpfs rw,mode=01777 0 0 > > When using the above in /etc/fstab to establish a tmp file, > how does the size of /tmp get established? > Is it limited only by the available swap, > or is it possible to put an upper bound on it that is smaller than swap? It's free VM, which should be available RAM plus available swap. Yes, you can easily limit the maximum size: tmpfs /tmp tmpfs rw,mode=01777,size=1073741824 0 0 Untested, but I think that's correct. There was a nice Sun white paper by Peter Snyder on tmpfs. It's linked on the Wikipedia tmpfs page, but Oracle has broken the link. Google has a rendered version of a PostScript copy (long URL): http://webcache.googleusercontent.com/search?q=cache:EXMeqvhFfrsJ:www.sun3arc.org/papers/OS/tmpfs_virtual_memory_filesystem.ps.gz+tmpfs+white+paper&cd=12&hl=en&ct=clnk&gl=us