ZFS panic at boot when mounting root on r330386

> panic: solaris assert: refcount_count(&spa->spa_refcount) > spa->spa_minref || MUTEX_HELD(&spa_namespace_lock), file: /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_misc.c, line: 952
> cpuid = 10
> time = 1520207367
> KDB: stack backtrace:
> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe23f57a2420
> vpanic() at vpanic+0x18d/frame 0xfffffe23f57a2480
> panic() at panic+0x43/frame 0xfffffe23f57a24e0
> assfail() at assfail+0x1a/frame 0xfffffe23f57a24f0
> spa_close() at spa_close+0x5d/frame 0xfffffe23f57a2520
> spa_get_stats() at spa_get_stats+0x481/frame 0xfffffe23f57a2700
> zfs_ioc_pool_stats() at zfs_ioc_pool_stats+0x25/frame 0xfffffe23f57a2740
> zfsdev_ioctl() at zfsdev_ioctl+0x76b/frame 0xfffffe23f57a27e0
> devfs_ioctl() at devfs_ioctl+0xcb/frame 0xfffffe23f57a2830
> VOP_IOCTL_APV() at VOP_IOCTL_APV+0x102/frame 0xfffffe23f57a2860
> vn_ioctl() at vn_ioctl+0x124/frame 0xfffffe23f57a2970
> devfs_ioctl_f() at devfs_ioctl_f+0x1f/frame 0xfffffe23f57a2990
> kern_ioctl() at kern_ioctl+0x2c2/frame 0xfffffe23f57a29f0
> sys_ioctl() at sys_ioctl+0x15c/frame 0xfffffe23f57a2ac0
> amd64_syscall() at amd64_syscall+0x786/frame 0xfffffe23f57a2bf0
> fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe23f57a2bf0
> --- syscall (54, FreeBSD ELF64, sys_ioctl), rip = 0x80049afda, rsp = 0x7fffffffbd18, rbp = 0x7fffffffbd90 ---
> KDB: enter: panic
> [ thread pid 56 tid 100606 ]
> Stopped at      kdb_enter+0x3b: movq    $0,kdb_why
> db>

It seems like a race as I can get it to boot sometimes.

-- 
Regards,
Bryan Drewery