Duplicating Minidisks

Directory Manager Guide › Managing Minidisks › Duplicating Minidisks

Duplicating Minidisks

Another method of creating minidisks is to create a duplicate of an existing minidisk. The resulting minidisk will be an exact duplicate of the source minidisk, having the same size, device type, label and other attributes. This feature is useful if you are creating many new minidisks, but want the new minidisks to have the same attributes and contents.

While the command can be used to duplicate a CMS minidisk, its real benefit is in cloning Linux images on VM. By first making a master image and then using the DUPMDISK command to duplicate the directory entry and the minidisks, you can quickly set up multiple identical Linux images.

Before you duplicate a minidisk, you must decide several details about it:

Minidisk feature	Default value	How to learn the default value
Directory entry and virtual address of the source minidisk (the one being duplicated)	none	N/A
Directory entry and virtual address of the new minidisk	none	N/A
Subpool where minidisk will be created	First subpool listed on your MANAGER record	vmdirect query subpool
Volser where the new minidisk will be allocated	Depends on the definition of the subpool	vmdirect config dasd
Location on the real volume	Depends on the definition of the subpool	vmdirect config dasd
Link mode	W	N/A
Read, write, multiple passwords	No passwords	N/A

Important! CA VM:Director reserves virtual addresses in the range 600 to 6FF for its own use. Do not assign minidisks to CA VM:Director in this range because CA VM:Director will attempt to reclaim them.

To create a duplicate minidisk, enter the DUPMDISK command from CMS. For example, to duplicate user RUBCA05's 191 disk as user SAVDI02's 194 disk, enter the following:

vmdirect dupmdisk rubca05 191 savdi02 194

Note: You must be the directory manager for both of the directory entries specified.

You can also specify options on the command to define a subpool from which to allocate space for the new minidisk, and specify a volser, location, link mode, and passwords.

Note: For more information about these and other options, see DUPMDISK Command in the Reference Guide.

If your site uses the Servant Facility, you can specify the NOWAIT option to return to CMS and your other work while the minidisk is duplicated. CA VM:Director sends informational messages to you in a spool file from the servant machine that completed the task.

If your site does not use the Servant Facility, you must wait for the minidisk to be duplicated before you can return to your other work. CA VM:Director displays informational messages near the bottom of your screen during the duplication process.