panic: ffs_blkfree: bad size
Starting stack trace...
panic(ffffffff827c62e5) at panic+0x159 sys/kern/subr_prf.c:229
ffs_blkfree(fffffd807820f698,31121f292abd13fa,4000) at ffs_blkfree+0xa42 sys/ufs/ffs/ffs_alloc.c:1296
ffs_indirtrunc(fffffd807820f698,fffffffffffffff4,227180,0,0,ffff8000216c2338) at ffs_indirtrunc+0x65d sys/ufs/ffs/ffs_inode.c:545
ffs_truncate(fffffd807820f698,33fa8,0,fffffd807f7d7888) at ffs_truncate+0xfd9 sys/ufs/ffs/ffs_inode.c:337
ffs_write(ffff8000216c2570) at ffs_write+0x924
VOP_WRITE(fffffd805faf3128,ffff8000216c2620,3,fffffd807f7d7888) at VOP_WRITE+0xc3 sys/kern/vfs_vops.c:245
ktrwriteraw(ffff800021633008,fffffd805faf3128,fffffd807f7d7888,ffff8000216c26e0,ffff8000216c26c0) at ktrwriteraw+0x14a sys/kern/kern_ktrace.c:664
ktrstruct(ffff800021633008,ffffffff8276fab2,ffff8000216c2820,10) at ktrstruct+0x156 ktrwrite2 sys/kern/kern_ktrace.c:627 [inline]
ktrstruct(ffff800021633008,ffffffff8276fab2,ffff8000216c2820,10) at ktrstruct+0x156 sys/kern/kern_ktrace.c:308
thrsleep(ffff800021633008,ffff8000216c2890) at thrsleep+0x100 sys/kern/kern_synch.c:636
sys___thrsleep(ffff800021633008,ffff8000216c2890,ffff8000216c28e0) at sys___thrsleep+0xb5 sys/kern/kern_synch.c:718
syscall(ffff8000216c2960) at syscall+0x4a8 sys/arch/amd64/amd64/trap.c:623
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x23fd3cb60, count: 245
End of stack trace.
syncing disks...23 20  done

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 860ebdd0-427f-2be6-5726-fd56b385017a
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 0x000f28a0: 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 3.65
boot> set $lines = 0
set: syntax error
boot> set $maxwidth = 0
set: syntax error
boot> show panic
boot: illegal argument panic
boot> trace
boot> show registers
boot> show proc
boot> ps
boot> show all locks
boot> show malloc
boot> show all pools
boot> machine ddbcpu 0
machine: syntax error
boot> trace
boot> machine ddbcpu 1
machine: syntax error
boot> trace