Date: Tue, 03 Nov 1998 16:50:27 -0500 From: Graeme Tait <graeme@echidna.com> To: freebsd-questions@FreeBSD.ORG Subject: File system performance Message-ID: <363F7AA3.22254A9C@echidna.com>
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I have a situation that involves manipulating large numbers of small files of about 1k each. I recently noticed a strange performance comparison between my "play" system (a 486-DX2/66/16MB with run-of-the-mill IDE drives and a Promise caching controller, running 2.2.6R) and "production" system (Pentium-II/400/256MB with Ultra 2 LVD SCSI and 4.5GB Seagate Cheetah drives, running 2.2.7S/CAM). When deleting these files (rm -rf), the 486 does it with a minimum of fuss (no trashing of the disk heads) at about 120 files a second. Disk operations occur ever second or so with intervals between. The production system only manages about 40 files a second, and you can hear that the disk heads are going for their life, vibrating back and forth between tracks. It's impressive to hear the speed of the head positioning, but the end result is hardly so. In both cases, the files being deleted were expanded from the same archive, into a relatively empty filesystem (built with the default fragment size, etc.). Similar behaviour occurs when the gzipped archive is expanded, but in this case the systems are about equal in speed. In other filesystem comparisions, with larger files, the production system runs rings around the test system, as you would expect. What is happening here? Is maybe something configured wrong on the production system? -- Graeme Tait - Echidna To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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