syncing disks...panic: ffs_update: bad link cnt
Starting stack trace...
panic(ffffffff8260f92f) at panic+0x155 sys/kern/subr_prf.c:229
ffs_update(fffffd80660c7698,0) at ffs_update+0x303 sys/ufs/ffs/ffs_inode.c:101
VOP_FSYNC(fffffd807bf147f8,fffffd807f7d75b0,2,ffff8000216f07e0) at VOP_FSYNC+0xc5 sys/kern/vfs_vops.c:311
ffs_sync_vnode(fffffd807bf147f8,ffff800029a516c0) at ffs_sync_vnode+0x180 sys/ufs/ffs/ffs_vfsops.c:1197
vfs_mount_foreach_vnode(ffff8000006d9000,ffffffff81ec1970,ffff800029a516c0) at vfs_mount_foreach_vnode+0x55 sys/kern/vfs_subr.c:910
ffs_sync(ffff8000006d9000,2,0,fffffd807f7d75b0,ffff8000216f07e0) at ffs_sync+0x11f sys/ufs/ffs/ffs_vfsops.c:1248
sys_sync(ffff8000216f07e0,0,0) at sys_sync+0xbc sys/kern/vfs_syscalls.c:537
vfs_syncwait(ffff8000216f07e0,1) at 
vfs_syncwait+0x36
vfs_shutdown(ffff8000216f07e0) at vfs_shutdown+0x5d sys/kern/vfs_subr.c:1791
boot(100) at boot+0xbb sys/arch/amd64/amd64/machdep.c:830
reboot(100) at reboot+0x77
panic(ffffffff8256b567) at panic+0x175 sys/kern/subr_prf.c:231
vop_generic_badop(ffff800029a51978) at vop_generic_badop+0x1b sys/kern/vfs_default.c:133
VOP_STRATEGY(fffffd8069546040,fffffd80686df820) at VOP_STRATEGY+0x9b sys/kern/vfs_vops.c:628
bwrite(fffffd80686df820) at bwrite+0x1e7 sys/kern/vfs_bio.c:760
VOP_BWRITE(fffffd80686df820) at VOP_BWRITE+0x4a sys/kern/vfs_vops.c:640
ufs_mkdir(ffff800029a51c10) at ufs_mkdir+0x6b4 sys/ufs/ufs/ufs_vnops.c:1236
VOP_MKDIR(fffffd8068e8dbd0,ffff800029a51d70,ffff800029a51da0,ffff800029a51ca0) at VOP_MKDIR+0xbf sys/kern/vfs_vops.c:388
domkdirat(ffff8000216f07e0,ffffff9c,7f7fffff3670,1ff) at domkdirat+0x121 sys/kern/vfs_syscalls.c:3112
syscall(ffff800029a51f20) at syscall+0x447 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0x7f7fffff36e0, count: 236
End of stack trace.

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 0x000f24c0: 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> 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