2009/7/17 David Gerard dgerard@gmail.com:
The ZFS bug manifests when the file system is (a) very full (b) getting lots of writes. The block allocation algorithm uses up all the CPU trying for perfection rather than adequacy. So system CPU goes through the roof and the system turns to molasses. Only way out: reboot - stopping writes or severely reducing the disk usage didn't work for us on Solaris 10.
And today I happened to be chatting to another Solaris 10 administrator who has seen precisely the same bug manifest itself on a terabyte zpool getting lots of I/O. So that's three cases. I certainly hope Sun get to the bottom of this one sooner rather than later ... and that btrfs gets out of alpha sooner than later.
- d.