I'm observing some strange behavior that I hope someone might be able to explain...
I run the following script: zpool create zpool c0t5000C50041ABABABd0 zfs create -V 200G -b 4k zpool/zvol zfs set logbias=throughput zpool/zvol zfs set primarycache=none zpool/zvol zfs set secondarycache=none zpool/zvol ./zvol_wce /dev/zvol/rdsk/zpool/zvol 1 vdbench -f Zvol_var I'm using the zvol_wce program that is described on Milak's blog to enable write caching. (I understand that it disables synchronize cache operation on each write) I turn off IO throttling (via 'echo zfs_no_write_throttle/w1 |mdb -kw'). I run write sequential operations using xfersize=4k and specify o_dsync and o_rsync in vdbench. I'm getting 200+MB/sec reported as the throughput (via vdbench) when the drive can only do 147 MB/sec. Another observation... when I control c the program, it takes 10+ secs to terminate, and there continues to be IO to the drive during the terminaton. (Seen via iostat) When either io throttling is disabled or I don't turn on WCE, vdbench reports <10 MB/sec and the problem will terminate normally. The $64,000 question is... why? Thanks! ------------------------------------------- illumos-discuss Archives: https://www.listbox.com/member/archive/182180/=now RSS Feed: https://www.listbox.com/member/archive/rss/182180/21175430-2e6923be Modify Your Subscription: https://www.listbox.com/member/?member_id=21175430&id_secret=21175430-6a77cda4 Powered by Listbox: http://www.listbox.com
