This example begins with a trans metadevice, d1, containing a mounted file system, and ends up with the file system mounted on the trans metadevice`s underlying master device, which will be d1.
# metastat d1 d1: Trans State: Okay Size: 5600 blocks Master Device: d21 Logging Device: d0 d21: Mirror Submirror 0: d20 State: Okay Submirror 1: d2 State: Okay ... d0: Logging device for d1 State: Okay Size: 5350 blocks # umount /fs2 # metadetach d1 d1: logging device d0 is detached # metarename -f -x d1 d21 d1 and d21 have exchanged identities # metastat d21 d21: Trans State: Detached Size: 5600 blocks Master Device: d1 d1: Mirror Submirror 0: d20 State: Okay Submirror 1: d2 State: Okay # metaclear 21 # fsck /dev/md/dsk/d1 ** /dev/md/dsk/d1 ** Last Mounted on /fs2 ** Phase 1 - Check Blocks and Sizes ** Phase 2 - Check Pathnames ** Phase 3 - Check Connectivity ** Phase 4 - Check Reference Counts ** Phase 5 - Check Cyl groups FILE SYSTEM STATE IN SUPERBLOCK IS WRONG; FIX? y 3 files, 10 used, 2493 free (13 frags, 310 blocks, 0.5% fragmentation) # mount /fs2 |
The metastat command confirms that the trans metadevice, d1, is in the "Okay" state. The file system is unmounted before detaching the trans metadevice's logging device. The trans metadevice and its mirrored master device are exchanged using the -f (force) flag. Running metastat again confirms that the exchange occurred. The trans metadevice and the logging device (if desired) are cleared, in this case, d21 and d0, respectively. Next, the the fsck command is run on the mirror, d1, and the prompt is answered with a y. After the fsck command is done, the file system is remounted. Note that because the mount device for /fs2 did not change, the /etc/vfstab file does not require editing.