panic: mtx_lock() of destroyed mutex @ /usr/src/sys/kern/vfs_subrc:2467 cpuid = 1 I was doing a zfs destroy -r of a dataset. The dataset has had many snapshot receives done. # uname -a FreeBSD 8.0-RC1 FreeBSD 8.0-RC1 #1: Tue Oct 13 14:11:08 CEST 2009 root@:/usr/obj/usr/src/sys/DEBUG amd64 (kernel config: added WITNESS, etc to have debugging information, doing some ZFS send/receive tests) It's a VMWare virtual machine, and I've frozen it. Borja.