panic: trap type 4, code=0, pc=ffffffff81ad533e
Starting stack trace...
panic(ffffffff8338d890) at panic+0x1ba sys/kern/subr_prf.c:229
kerntrap(ffff80002a772ef0) at kerntrap+0x2fb
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
mtx_enter(dead4110dead41f0) at mtx_enter+0x6e sys/kern/kern_lock.c:545
prsignal(dead4110dead4110,14) at prsignal+0x36 sys/kern/kern_sig.c:904
reaper(ffff80002a73d758) at reaper+0x2bc sys/kern/kern_exit.c:516
end trace frame: 0x0, count: 251
End of stack trace.
syncing disks...37 32 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1  giving up

dump to dev 4,1 not possible
rebooting...
SeaBIOS (version 1.8.2-google)
Total RAM Size = 0x0000000080000000 = 2048 MiB
CPUs found: 2     Max CPUs supported: 2
SeaBIOS (version 1.8.2-google)
Machine UUID d662f6a5-d763-0b53-7cd8-e4e6b0001699
found virtio-scsi at 0:3
virtio-scsi vendor='Google' product='PersistentDisk' rev='1' type=0 removable=0
virtio-scsi blksize=512 sectors=4194304 = 2048 MiB
drive 0x000f26e0: PCHS=0/0/0 translation=lba LCHS=520/128/63 s=4194304
Sending Seabios boot VM event.
Booting from Hard Disk 0...
>> OpenBSD/amd64 BOOT 3.67
boot> show all pools
boot: illegal argument all
boot> machine ddbcpu 0
machine: syntax error
boot> trace
boot> machine ddbcpu 1
machine: syntax error
boot> trace