A specific procedure must be used when replacing one of the two
internal fibre channel disks in a SunFire 280R system if the disk is under
Veritas Volume Manager (VxVM) control.  Although these disks are
hot-swappable, the procedure below should be used to alert VxVM to
the fact that the drive is being replaced.  This document applies to to 
Veritas Volume Manager (VxVM) 3.x.  This document also assumes that you 
are running either Solaris 8, or Solaris 7 with kernel patch 106541-08 or
higher.  This is required to get the functionality of the devfsadm command.

Failure to follow this procedure could result in a duplicate entry for
the replaced disk in VxVM.  This is most notable when running a 'vxdisk list'.
For example:
   
   # vxdisk list
   DEVICE       TYPE      DISK         GROUP        STATUS
   c1t0d0s2     sliced    rootdisk     rootdg       online
   c1t1d0s2     sliced    -            -            error
   c1t1d0s2     sliced    -            -            error

The extra device will disappear after the next reboot, which seems to be
the only way to remove it. Therefore it is best to prevent the duplicate 
device from being created in the first place. This is accomplished by the
following procedure:
                    ----------------------
Before replacing any disk under VxVM control, it should be either in a
'failed' or 'removed' state.  If the disk does not show up as "failed
was", as shown here:

   # vxdisk list
   DEVICE       TYPE      DISK         GROUP        STATUS
   c1t0d0s2     sliced    rootdisk     rootdg       online
   c1t1d0s2     sliced    -            -            online
   -            -         disk01       rootdg       failed was:c1t1d0s2

then you should run 'vxdiskadm' and choose option #4 to remove the disk
for replacement.  After running 'vxdiskadm', the output should look
like this:

   # vxdisk list
   DEVICE       TYPE      DISK         GROUP        STATUS
   c1t0d0s2     sliced    rootdisk     rootdg       online
   c1t1d0s2     sliced    -            -            online
   -            -         disk01       rootdg       removed was:c1t1d0s2


1. Once the disk is in one of the two states shown above, put the disk into the 
   "offline" state with the following command:

      # vxdisk offline c1t1d0s2

2. Once the disk shows up in the "offline" state, it is safe to physically
   replace the disk.

3. After replacing the disk, create the necessary entries in the Solaris 
   device tree with the following the command:

      # devfsadm -C

4. To cause VxVM to re-read the device tree, run the command

      # vxdctl enable

5. The disk will remain in the "offline" state until you initialize the new
   disk.  To initialize it, use either the command line

      # vxdisksetup -i c1t1d0

   or run 'vxdiskadm' and choose option #5 to initialize it and replace the
   failed or removed disk.  If you choose to run 'vxdiskadm' and choose 
   option #5, you will be told that "Access is disabled" for this new disk
   (because it is still "offline"), and will be asked whether or not you
   wish to "enable access" to it.  Obviously, answer 'yes' to this question.

                                    

Keywords: VxVM, Volume Manager, upgrade, upgrading, configure, configured, configuration