Date: Sat, 12 Jun 2010 12:36:22 -0300 From: Thiago Damas <tdamas@gmail.com> To: freebsd-hackers@freebsd.org Subject: strange zfs behavior Message-ID: <AANLkTikUPWNC7j4nKKfV2pAdzhDnBOpBGjxLC5ymJCZT@mail.gmail.com>
next in thread | raw e-mail | index | archive | help
Hi, I'm testing some configuration using ZFS with 4 disks seagate: ad4: 953869MB <Seagate ST31000528AS CC38> at ata2-master UDMA100 SATA 3Gb/s ad6: 953869MB <Seagate ST31000528AS CC38> at ata3-master UDMA100 SATA 3Gb/s ad8: 953869MB <Seagate ST31000528AS CC38> at ata4-master UDMA100 SATA 3Gb/s ad10: 953869MB <Seagate ST31000528AS CC38> at ata5-master UDMA100 SATA 3Gb/s The system its amd64 8.1-BETA1 (tested too in 8.0-p3). My only tuning its (in /boot/loader.conf): vm.kmem_size_scale="2" vfs.zfs.txg.timeout=5 The machine has 4Gb RAM, and SATA controller its LSI53C1020/1030 (adaptec 1020) At first, I used the following: zpool create -f -m /storage tank mirror /dev/ad4 /dev/ad6 mirror /dev/ad8 /dev/ad10 and I noticed ad10 slower than others (svc_t) svc_t: http://i48.tinypic.com/34s1ndd.gif http://i45.tinypic.com/m9x6ra.gif wait: http://i47.tinypic.com/2uqksv5.gif http://i49.tinypic.com/200qza9.gif Now, I swapped the configuration: zpool create -f -m /storage tank mirror /dev/ad10 /dev/ad8 mirror /dev/ad6 /dev/ad4 and now I have ad4 slower than others svc_t: http://i49.tinypic.com/2uxtqww.gif http://i50.tinypic.com/10dbcix.gif wait: http://i46.tinypic.com/331f5lf.gif http://i46.tinypic.com/2lc7c5k.gif Will always the last disk in zfs configuration perform like that? Any comments?
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?AANLkTikUPWNC7j4nKKfV2pAdzhDnBOpBGjxLC5ymJCZT>