From owner-freebsd-fs@FreeBSD.ORG Mon Jun 5 02:25:21 2006 Return-Path: X-Original-To: freebsd-fs@freebsd.org Delivered-To: freebsd-fs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AAAEC16A512 for ; Mon, 5 Jun 2006 02:25:21 +0000 (UTC) (envelope-from anderson@centtech.com) Received: from mh2.centtech.com (moat3.centtech.com [207.200.51.50]) by mx1.FreeBSD.org (Postfix) with ESMTP id 54B7D43D46 for ; Mon, 5 Jun 2006 02:25:21 +0000 (GMT) (envelope-from anderson@centtech.com) Received: from [192.168.42.22] (andersonbox2.centtech.com [192.168.42.22]) by mh2.centtech.com (8.13.1/8.13.1) with ESMTP id k552PE9a069517; Sun, 4 Jun 2006 21:25:17 -0500 (CDT) (envelope-from anderson@centtech.com) Message-ID: <4483960F.5000102@centtech.com> Date: Sun, 04 Jun 2006 21:25:19 -0500 From: Eric Anderson User-Agent: Thunderbird 1.5.0.2 (X11/20060506) MIME-Version: 1.0 To: Duane Whitty References: <6845d25a0606041436j5f964aeeo7bc02b61b98b790a@mail.gmail.com> <20060604214841.GC960@dwpc.dwlabs.ca> In-Reply-To: <20060604214841.GC960@dwpc.dwlabs.ca> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: ClamAV 0.87.1/1512/Sun Jun 4 04:58:49 2006 on mh2.centtech.com X-Virus-Status: Clean Cc: freebsd-fs@freebsd.org, Dave Stephens Subject: Re: capacity issue? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Jun 2006 02:25:23 -0000 Duane Whitty wrote: > On Sun, Jun 04, 2006 at 05:36:41PM -0400, Dave Stephens wrote: >> OS Version: FreeBSD 6.1 >> >> It seems like the capacity of my drive is being reported incorrectly >> by df. I'm not sure if this is a specific issue with the SATA drive >> or controller in the server, but I figured I would ask around. There >> is only 1 physical drive in this server. >> >> SATA Drive >> -------------------------------------------------------------------------------- >> ad8: 286168MB at ata4-master SATA150 >> >> SATA Controllers >> -------------------------------------------------------------------------------- >> atapci1: port >> 0xeff0-0xeff7,0xefe4-0xefe7,0xefa8-0xefaf,0xefe0-0xefe3,0xef >> 90-0xef9f irq 17 at device 5.0 on pci0 >> ata2: on atapci1 >> ata3: on atapci1 >> atapci2: port >> 0xefa0-0xefa7,0xef8c-0xef8f,0xef80-0xef87,0xef88-0xef8b,0xe >> f60-0xef6f mem 0xfebfac00-0xfebfadff irq 17 at device 9.0 on pci0 >> ata4: on atapci2 >> ata5: on atapci2 >> >> Note that atapci1 is built onto the motherboard and doesn't seem to be >> supported by FreeBSD at this time (no HDDs can be found during install >> when they are attached to it.) >> >> Mounting (dmesg) >> -------------------------------------------------------------------------------------------- >> swapon: adding /dev/ad8s2b as swap device >> Starting file system checks: >> /dev/ad8s1a: FILE SYSTEM CLEAN; SKIPPING CHECKS >> /dev/ad8s1a: clean, 221765 free (2981 frags, 27348 blocks, 1.2% >> fragmentation) >> /dev/ad8s4d: FILE SYSTEM CLEAN; SKIPPING CHECKS >> /dev/ad8s4d: clean, 9668716 free (980 frags, 1208467 blocks, 0.0% >> fragmentation) >> /dev/ad8s4f: FILE SYSTEM CLEAN; SKIPPING CHECKS >> /dev/ad8s4f: clean, 51380314 free (18 frags, 6422537 blocks, 0.0% >> fragmentation) >> /dev/ad8s3d: FILE SYSTEM CLEAN; SKIPPING CHECKS >> /dev/ad8s3d: clean, 28290946 free (32938 frags, 3532251 blocks, 0.1% >> fragmentation) >> /dev/ad8s3e: FILE SYSTEM CLEAN; SKIPPING CHECKS >> /dev/ad8s3e: clean, 9904253 free (1589 frags, 1237833 blocks, 0.0% >> fragmentation) >> /dev/ad8s4e: FILE SYSTEM CLEAN; SKIPPING CHECKS >> /dev/ad8s4e: clean, 37032718 free (998 frags, 4628965 blocks, 0.0% >> fragmentation) >> >> output from df >> --------------------------------------------------------------------------------- >> Filesystem Size Used Avail Capacity Mounted on >> /dev/ad8s1a 494M 61M 394M 13% / >> devfs 1.0K 1.0K 0B 100% /dev >> /dev/ad8s4d 19G 497M 17G 3% /home >> /dev/ad8s4f 98G 1.4G 89G 2% /photo >> /dev/ad8s3d 57G 2.8G 49G 5% /usr >> /dev/ad8s3e 19G 46M 17G 0% /var >> /dev/ad8s4e 76G 5.0G 65G 7% /www >> >> last time i checked (just as examples) >> 98G - 1.4G is not 89G (/photo) >> 57G - 2.8G is not 49G (/usr) >> 76G - 5.0G is not 65G (/www) >> >> Can anyone tell me what's going on here? >> >> Dave >> _______________________________________________ > > Hi, > > Avail = (Size - "elbow room") - Used > > The FFS algorithms need a little free space, about 5% I think, > in order to function efficiently. This is also why you can > df report a disk more than 100% used. > > Hth, > > Duane Whitty Right, it's 8% unless specified otherwise. Root is the only user that can use the reserved 8%, but usage of that space causes fragmentation and a performance penalty. Eric -- ------------------------------------------------------------------------ Eric Anderson Sr. Systems Administrator Centaur Technology Anything that works is better than anything that doesn't. ------------------------------------------------------------------------