HP OpenVMS Systems Documentation

Content starts here 7.7 Forming the Shadow Set
HP OpenVMS Version 8.4 Upgrade and Installation Manual > Chapter 7 After Installing or Upgrading the OpenVMS Operating System

7.7 Forming the Shadow Set

If you have upgraded a disk in a volume shadowing environment, you must now re-form the shadow set. If you want to form a shadow set for a newly installed system disk, you can do this now or later. To do so requires that the VOLSHAD license has been entered and loaded. In addition, you must set several system parameters, as explained in Section 7.4, and then you must run AUTOGEN and reboot the system, as explained in Section 7.6.

Forming the shadow set with the newly installed or upgraded disk as the master causes the other disks in the shadow set to be updated with a copy of the disk. (In a single-member shadow set, although no other disks exist to be updated, the shadow set can be used to facilitate replacement of a failed drive.)

After forming the shadow set, dismount one of the shadow set members and keep it as a backup. After you perform the steps recommended in this chapter, you can place another volume into the shadow set instead of doing the final backup, or re-add the volume that was dismounted.

Form the shadow set as follows:

  1. Enter the SHOW DEVICE D command to display a list of disks available on your system. For example:

    Device                Device     Error    Volume       Free  Trans Mnt
     Name                 Status     Count    Label       Blocks Count Cnt
    $11$DKB100:  (NODE1)  Online        0  
    $11$DKB200:  (NODE1)  Mounted       0     I64084      918150    1  31
  2. Enter a command in the following format:

    MOUNT/CONFIRM/SYSTEM DSAn: /SHADOW=(upgraded-disk:,new-member:) volume-label


    • DSAn: is the virtual unit name of the shadow set, where n is a unique number from 0 to 999.

    • upgraded-disk: is the name of the shadowed system disk on which you just upgraded or installed OpenVMS.

    • new-member: is the name of the disk you want to add as a member of the shadow set.

    • volume-label is the volume label of the shadow set you just upgraded or the disk you are creating.

    NOTE: When you form the shadow set, the contents of the new member are replaced by the contents of the disk you upgraded. Specifying the /CONFIRM qualifier reminds you of this fact, confirming that you are specifying the correct name of a disk that either is blank or contains files you no longer need.


$ MOUNT/CONFIRM/SYSTEM DSA54: /SHADOW=($11$DKB200:,$11$DKB100:) I64084 

%MOUNT-F-SHDWCOPYREQ, shadow copy required 
Virtual Unit - DSA54 Volume label I64A084
     Member                    Volume label Owner UIC
     $11$DKB100:  (NODE1)      SCRATCH      [100,100] 
Allow FULL shadow copy on the above member(s)? [N]: YES
NOTE: Before continuing with the next step in this chapter, after the shadow copy completes, dismount one of the shadow set members to use as a backup. Normally, this should be the unit you just added to the upgraded volume when you formed the shadow set (in the preceding example, $11$DKB100:).

For OpenVMS Integrity servers, to add a shadowed system disk in a multiple-member shadow set to the EFI boot device list and dump device list, HP recommends using the OpenVMS Integrity servers Boot Manager utility (SYS$MANAGER:BOOT_OPTIONS.COM). Be sure to add all members to both lists.