  Splitting volume shadowset during product upgrade? 
 The Question is:
 
I plan to perform an upgrade of two layered products (basic and cms)
 
Since I currently have a shadowed system disk consisting of two physical
volumes can I boot up the system and do the upgrades with just one volume
spun up and if I have problems with the upgrade can I reboot using the 2ed
volume to
back out the installation?  Or is this to complicated for the effort?
 
 
 
 
 
 The Answer is:
 
  The Wizard would recommend simply installing the BASIC and DECset kits
  -- the OpenVMS Wizard would not recommend splitting up the volume
  shadowset for this purpose.
 
  If you are considering the "split shadowset" approach, you will want to
  review your system disk BACKUP strategy and your on-site and off-site
  archives -- the volume shadowing product provides better tolerance of
  potential storage hardware problems, but does not particularly provide
  for better tolerance of layered product installation failures, random
  file deletions or corruptions, and/or various other application or user
  errors.  (Only system disk BACKUPs can permit you to quickly and easily
  recover from a variety of common errors that can potentially arise.)
 
  If you choose to split the volume shadowset, you will have to check and
  change your console setting for the boot command (the exact syntax for
  a bootstrap from a volume shadowset is system-specific), and you will
  want to take the alternative ("archived") volume offline during the
  upgrade operation.  Once you have completed the upgrade, initialize
  the older copy of the shadowset and (very carefully) merge the volume
  back into the existing shadowset using MOUNT to add a "new" volume into
  the existing shadowset.  Then shut down the system and reset the console
  to boot from any available shadowset volume, and reboot.
 
  Due to the potential for the older shadowset volume to be selected as the
  latest volume due to various potential command-level errors, the OpenVMS
  Wizard does not recommend this approach.  That said, ensure you have a
  valid and recent system disk BACKUP/IMAGE available.
 
