Disaster Recovery

If the /devices or /dev directories are damaged—most likely to occur if the driver crashes during attach(9E)—they can be re-created by booting the system and running fsck(1M) to repair the damaged root file system. The root file system can then be mounted. Re-create /dev and /devices by running devfsadm(1M) and specifying the /devices directory on the mounted disk.

On SPARC, for example, if the damaged disk is /dev/dsk/c0t3d0s0, and an alternate boot disk is /dev/dsk/c0t1d0s0, do the following:

ok boot disk1
...
Rebooting with command: boot kernel.test/unix
Boot device: /sbus@1f,0/espdma@e,8400000/esp@e,8800000/sd@31,0:a  File and args:
kernel/unix
SunOS Release 5.9 Version Generic 32-bit
Copyright 1983-2002 Sun Microsystems, Inc.  All rights reserved.
...
# fsck /dev/dsk/c0t3d0s0** /dev/dsk/c0t3d0s0
** Last Mounted on /
** Phase 1 - Check Blocks and Sizes
** Phase 2 - Check Pathnames
** Phase 3 - Check Connectivity
** Phase 4 - Check Reference Counts
** Phase 5 - Check Cyl groups
1478 files, 9922 used, 29261 free
     (141 frags, 3640 blocks, 0.4% fragmentation)
# mount /dev/dsk/c0t3d0s0 /mnt
# devfsadm -r /mnt

Fixing /devices and /dev may allow the system to boot, but other parts of the system can still be corrupted. This is only a temporary fix to allow saving information (such as system crash dumps) before reinstalling the system.