Partition(s) present but not detected after panic

[jb_daefo]

(This happened before with rsnapshot, each time the
panic was preceeded by access to the destination
filesystem. Planning to insert
#sync (multiple)
to the backup script to maybe avert the panic
again. If anyone knows of a mount option that
is less prone to the problem, it would be appreciated
(unless the sync's work)
))
The destination disk, /dev/ad10, I can mount:
"warning, [ ] was not properly dismounted"
but cannot fsck. I can see the subdir's within it when
mounted.
testdisk does not see /dev/ad10
scan_ffs iirc reports 'device not configured'
So it seems the only thing to do is re-partition, re-newfs
unless someone knows of a bsdlabel-or-similar
partition table recovery tool (for a valid mountable partition
that one cannot fsck nor fdisk nor testdisk...)
fdisk reports 'device not configured'
df shows it mounted and 13 percent in use.
.........