Date: Sun, 09 Feb 2003 20:03:24 +0100 From: Poul-Henning Kamp <phk@phk.freebsd.dk> To: arch@freebsd.org Subject: Our lemming-syncer caught in the act. Message-ID: <31118.1044817404@critter.freebsd.dk>
next in thread | raw e-mail | index | archive | help
I have suspected our syncer of being subobtimal for some time, based simply on my perception of the disk-light on my laptop and the dynamics of the "dirty" counter in systat. I played with the new GEOM I/O statistics stuff and guess what: I caught it in the act: http://phk.freebsd.dk/misc/disk.png Green is the number of unfinished requests. Most of the red "impulse" represents one request finishing after as many milliseconds as it is tall. The remainder of the impulses cover more than one request, the height is then the average of the time it has taken to service them. An image is worth a thousand words, but in this case it only says three words: "Man, that sucks!". Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?31118.1044817404>