Date: Wed, 13 Oct 1999 07:53:44 +0200 From: J Wunsch <j@uriah.heep.sax.de> To: patl@phoenix.volant.org Cc: freebsd-scsi@FreeBSD.ORG Subject: Re: Disktab entry for Seagate ST-19171W (Barracuda 9) Message-ID: <19991013075344.47656@uriah.heep.sax.de> In-Reply-To: <ML-3.4.939767500.2102.patl@asimov>; from patl@phoenix.volant.org on Tue, Oct 12, 1999 at 03:31:40PM -0700 References: <19991012234014.04359@uriah.heep.sax.de> <ML-3.4.939767500.2102.patl@asimov>
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As patl@phoenix.volant.org wrote: > I'd still like to find a disktab entry for the Barracuda 9 (ST-19171W). > In particular, I'd like advice on the geometry settings. The boot-time > probe reports it as: > > 8683MB (17783112 512 byte sectors: 64H 32 S/T 8683C) > > But the drive specs indicate 20 heads and only 17773440 sectors. (I > won't bother with the track/cylinder count since it appears to vary > the number of sectors per track.) You should not bother with either number at all. If you want a disk that's only there for FreeBSD, use "disktab -Bw da1 auto" to get a label that covers all the 17783112 blocks. However, due to the way newfs (and cylindergroups etc.) is working, there'll always be some wasted sectors at the end of a filesystem. OTOH, what's something like wasted 5 MB, compared to 8 GB total capacity? > My real question is would I get any performance gain if I change the > geometry... No. The default setup of newfs ignores geometry data to the best level that is possible, considering the underlying UFS technology that is somewhat aged already, and that's usually the best performance you'd get with a modern drive. -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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