ZFS Problem Reporting

In order to have at all a chance to debug ZFS issues, the FreeBSD developers usually need this information:

dmesg output (this will include relevant FreeBSD build dates, versions, architecture type, amount of RAM, and highly relevant disk/storage subsystem details)
Date of when your source was csup'd (if different from build date)
/boot/loader.conf file contents
/etc/sysctl.conf file contents
sysctl -a | grep zfs output
zpool status output
zfs get all output
top screen output (mainly the header portions, re: memory usage)
If I/O is slow, zpool iostat -v 1 output while the problem happens
Anything else they can think of that seems relevant (disk I/O graphs, or whatever you think might play a role)