LSI 9200-8e/gmultipath/ZFS cable pull kernel crash

[John D]

Hi Folks,

   Looking for a bit of help to debug a sas interconnect, gmultipath,
and zfs filesystem crash when the 2nd cable is pulled. Apologies for
the cross post to geom & fs, hoped I would catch the right folks.

   In general, I have two systems each with an LSI 9200-8e sas hba installed.
Each adapter has two cables going to shelf 1, then to shelf 2, then to the
second system.

System1 <---> Shelf1 <---> Shelf2 <---> System2
System1 <---> Shelf1 <---> Shelf2 <---> System2

   Typical stuff, system1 & 2 are carp'd together, if one system
goes down, the second zfs imports the pools and takes over.

   If I do a test pull of one of the cables, multipath removes the failed
providers correctly with no interupt to the filesystem. Reinstalling the
cable causes the providers to be re-integrated. This cable can be pull/reinstalled
multiple times with no problem. However, pulling the 2nd causes a kernel
crash.

   I have the configuration/logs/screen shots here:

http://people.freebsd.org/~jwd/lsi_gmultipath_zfs.html

   I can replicate the problem on demand. Any help debugging this problem
is appreciated.

Thanks!
john