Date: Sun, 25 Apr 2010 13:51:00 +0200 From: Anselm Strauss <amsibamsi@gmail.com> To: freebsd-questions@freebsd.org Subject: ZFS scheduling Message-ID: <4BD42CA4.8050201@gmail.com>
next in thread | raw e-mail | index | archive | help
Hi, I noticed that my system gets very slow when I'm doing some simple but intense ZFS operations. For example, I move about 20 Gigabytes of data from one data set to another on the same pool, which is a RAIDZ of 3 500 GB SATA disks. The operations itself runs fast, but meanwhile other things get really slow. E.g. opening a application takes 5 times as long as before. Also simple operations like 'ls' stall for some seconds which they did never before. It already changed a lot when I switched from RAIDZ to a mirror with only 2 disks. Memory and CPU don't seem to be the issue, I have a quad-core CPU and 8 GB RAM. I can't get rid of the idea that this has something to do with scheduling. The system is absolutely stable and fast. Somehow small I/O operations on ZFS seem to have it very difficult to make it through when other bigger ones are running. Maybe this has something to do with tuning? I know my system information is very incomplete, and there could be a lot of causes. But anybody knows if this could be an issue with ZFS itself? Thanks, Anselm
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4BD42CA4.8050201>