Our latency problems went away like a miracle when we detached one half of the mirror (so it is no more a mirror). Read-Rates are doubled (not per device, the total read rate!), latency is cut off. No more latency problems. When attaching the volume again, resilvering puts the system to a halt - reads and writes do block for seconds (!). We will go on directly with Sun to solve the problem. Their "lowest I/O-priority to resilver disks" does not seem to be effective. It really blocks the kernel and you end up with thousand locks in "zfs_zget". We have two SAN volumes in different buildings which are NOT the bottleneck, tests show it. Pascal ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html