нагуглил сам
# ZFS tuning
# Mostly taken from: http://broken.net/uncategorized/zfs-performance-tuning-for-scrubs-and-resilvers/
vfs.zfs.l2arc_write_boost=160000000 # Set the L2ARC warmup writes to 160 MBps
vfs.zfs.l2arc_write_max=320000000 # Set the L2ARC writes to 320 MBps
vfs.zfs.resilver_delay=0 # Prioritise resilver over normal writes (default 2)
vfs.zfs.scrub_delay=0 # Prioritise scrub over normal writes (default 4)
vfs.zfs.top_maxinflight=128 # Up the number of in-flight I/O (default 32)
vfs.zfs.resilver_min_time_ms=5000 # Up the length of time a resilver process takes in each TXG (default 3000)
vfs.zfs.vdev.max_pending=24 # Set the queue depth (number of I/O) for each vdev
#--> # Set this really high. Then monitor the L(q) column in gstat under load.
#--> # Set it to just slightly lower than the highest number you see.
добавляем в sysctl.conf
# servise sysctl restart
Скорость выросла в 10 раз,и все уперлось в CPU.
scan: resilver in progress since Mon Nov 30 17:11:04 2015
5.36T scanned out of 5.74T at 101M/s, 1h7m to go
609G resilvered, 93.25% done
