=== DF-0867 panic signature (from dfbsd-qemu/boot.log) ===
Trigger: HAMMERIOC_MIRROR_WRITE with rec_type=0x0002, data_len=16

209:panic: hammer_alloc_data: rec_type 0002 unknown
210:cpuid = 0
211:Trace beginning at frame 0xfffff80117f59138
212:hammer_alloc_data() at hammer_alloc_data+0x184 0xffffffff8094ae44 
213:hammer_alloc_data() at hammer_alloc_data+0x184 0xffffffff8094ae44 
214:hammer_create_at_cursor() at hammer_create_at_cursor+0xf0 0xffffffff809437f0 
215:hammer_ioc_mirror_write() at hammer_ioc_mirror_write+0x3f8 0xffffffff809402d8 
216:hammer_ioctl() at hammer_ioctl+0xebe 0xffffffff8093ecce 
217:hammer_vop_ioctl() at hammer_vop_ioctl+0x48 0xffffffff80958978 
218:Debugger("panic")
222:Stopped at      Debugger+0x7c:  movb    $0,0xbdaf09(%rip)
223:db>