panic: trap type 4, code=0, pc=ffffffff8177538a
Starting stack trace...
panic(ffffffff8271eb23) at panic+0x155 sys/kern/subr_prf.c:229
kerntrap(ffff80002e882180) at kerntrap+0x1b7 sys/arch/amd64/amd64/trap.c:327
alltraps_kern_meltdown() at alltraps_kern_meltdown+0x7b
ktrops(ffff8000ffff55d0,dead4110dead4110,0,80000044,fffffd80775b3a50,fffffd807f7d7548) at ktrops+0x4a ktrcanset sys/kern/kern_ktrace.c:696 [inline]
ktrops(ffff8000ffff55d0,dead4110dead4110,0,80000044,fffffd80775b3a50,fffffd807f7d7548) at ktrops+0x4a sys/kern/kern_ktrace.c:541
doktrace(fffffd80775b3a50,4,44,0,ffff8000ffff55d0) at doktrace+0x514 ktrsetchildren sys/kern/kern_ktrace.c:566 [inline]
doktrace(fffffd80775b3a50,4,44,0,ffff8000ffff55d0) at doktrace+0x514 sys/kern/kern_ktrace.c:488
sys_ktrace(ffff8000ffff55d0,ffff80002e8824c8,ffff80002e882510) at sys_ktrace+0xd2 sys/kern/kern_ktrace.c:529
syscall(ffff80002e882590) at syscall+0x484 sys/arch/amd64/amd64/trap.c:600
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xfcb04fc2d0, count: 249
End of stack trace.
syncing disks...26 20 2 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 db0dc653-7a57-7afa-fd77-d87c02d918a4
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 0x000f2480: 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 3.55
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