syncing disks...panic: ffs_update: bad link cnt
Starting stack trace...
panic(ffffffff8260b16b) at panic+0x16b sys/kern/subr_prf.c:233
ffs_update(fffffd807bfd2de0,0) at ffs_update+0x303 sys/ufs/ffs/ffs_inode.c:101
VOP_FSYNC(fffffd8077440728,fffffd807f7d8660,2,ffff80002c950a80) at VOP_FSYNC+0xce sys/kern/vfs_vops.c:327
ffs_sync_vnode(fffffd8077440728,ffff80002e536b60) at ffs_sync_vnode+0x15a sys/ufs/ffs/ffs_vfsops.c:1191
vfs_mount_foreach_vnode(ffff8000006d5c00,ffffffff82514f70,ffff80002e536b60) at vfs_mount_foreach_vnode+0x55 sys/kern/vfs_subr.c:893
ffs_sync(ffff8000006d5c00,2,0,fffffd807f7d8660,ffff80002c950a80) at ffs_sync+0x11f sys/ufs/ffs/ffs_vfsops.c:1242
sys_sync(ffff80002c950a80,0,0) at sys_sync+0xbc sys/kern/vfs_syscalls.c:539
vfs_syncwait(ffff80002c950a80,1) at vfs_syncwait+0x36
vfs_shutdown(ffff80002c950a80) at vfs_shutdown+0x5d sys/kern/vfs_subr.c:1769
boot(100) at boot+0xc8 sys/arch/amd64/amd64/machdep.c:830
gfxhub_v2_1_get_fb_location(100) at gfxhub_v2_1_get_fb_location
panic(ffffffff82567b18) at panic+0x18b sys/kern/subr_prf.c:235
vop_generic_badop(ffff80002e536e28) at vop_generic_badop+0x1b sys/kern/vfs_default.c:133
VOP_STRATEGY(fffffd80647d0120,fffffd8058ba6db0) at VOP_STRATEGY+0x9b sys/kern/vfs_vops.c:644
bwrite(fffffd8058ba6db0) at bwrite+0x1f0 sys/kern/vfs_bio.c:763
VOP_BWRITE(fffffd8058ba6db0) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:656
ufs_mkdir(ffff80002e5370c0) at ufs_mkdir+0x6b4 sys/ufs/ufs/ufs_vnops.c:1248
VOP_MKDIR(fffffd80757fb7f0,ffff80002e537220,ffff80002e537250,ffff80002e537150) at VOP_MKDIR+0xbf sys/kern/vfs_vops.c:404
domkdirat(ffff80002c950a80,ffffff9c,7f7fffff77c0,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:3100
syscall(ffff80002e5373d0) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff80002e5373d0) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7fffff7830, count: 236
End of stack trace.

dump to dev 4,1 not possible
rpaebniooct:i nkger.ne..l
 diagnostic 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 70cc8852-3e3d-1621-491f-9b3abbe0e2d7
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 0x000f2500: 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 3.53
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