Hello, i have a very weird problem on a FSC RX300 Server machine (LSI Raid controller)
i first came across this when trying Nexenta-OS, but the problem remains with nv_109 and nv_110. the problem is: Writing to a ZFS volume is ok, but read performance sucks big. (slower by a factor of 5-10, maybe even more) if i format the same volume/slice with ufs, i don`t see this issue. the disks are hardware raid1 and raid5 volumes and i see the same behaviour on both. while reading from the disks (dd if=/zfs/path/to/file of=/dev/zero) , using mpstat i don`t see anything weird - there just isn`t "happening" anything -no large time spent in usr/sys and no large values for wait-I/O, no excessive high interrupts or context switching.... so, why is it slow and where does solaris spend it`s time when reading from disk? hints ? maybe scheduling/timer issue ? i don`t have a clue where to look at..... regards roland -- This message posted from opensolaris.org _______________________________________________ perf-discuss mailing list perf-discuss@opensolaris.org
