You use the parmlib member EDGRMMxx VLPOOL command to define
pools and to set actions that you want taken on all the volumes that
reside in the pool. The VLPOOL MASTEROVERWRITE operand controls how
DFSMSrmm allows the overwriting of a volume. You can specify if you
want to allow data to be appended to the end of a volume or overwritten,
or to allow new files to be added to a volume. The MASTEROVERWRITE
value applies to all volumes that reside in a pool. This diagram shows
the syntax of the VLPOOL MASTEROVERWRITE operand.
If you do not specify the VLPOOL MASTEROVERWRITE value, DFSMSrmm
uses the value that is set with the DFSMSrmm EDGRMMxx OPTION
MASTEROVERWRITE operand.
>>-VLPOOL------------------------------------------------------->
>--+---------------------------------------------------------+-><
| .-option_masteroverwrite_value-. |
'-MASTEROVERWRITE--(--+-MATCH------------------------+--)-'
+-USER-------------------------+
+-ADD--------------------------+
'-LAST-------------------------'
- ADD
- Specify this value so new data can be created and no existing
data can be destroyed. No existing file on a volume can be recreated,
but the last file can have new data added to it. When adding data
to the last file, DFSMSrmm checks that the data set name used must
match the existing data set name. Select this option when you want
the last file on the volume to be extended or a new file added to
the volume.
Note: DFSMSrmm enforces the MASTEROVERWRITE(ADD) option
on a WORM tape that is in master status. This is done to ensure that
you see a message from DFSMSrmm rather than one of a number of symptoms
as a result of the tape drive preventing overwrites.
- LAST
- Specify this value to ensure that when an existing file on a master
volume is being written to that only the last file on the volume can
be used. The data set name used must match the existing data set name.
Select this option when you want the last file on the volume to be
used for output.
- MATCH
- Specify this value to ensure that when an existing file on a master
volume is being used for output that exactly the same data set name
must be used. Select this option when you want any existing file on
the volume to be recreated regardless of whether it is the last file
on the volume as long as the same data set name is used.
When
you use an existing tape file for output all the files which are higher
in sequence are destroyed.
- USER
- Specify this value to allow any existing file on a master volume
to be used for output regardless of the data set names being used
and its relative file position on the volume. Select this option when
you want validation of master volumes to be just the same as for user
status volumes.
When you use an existing tape file for output
all the files which are higher in sequence are destroyed.
Default: The DFSMSrmm parmlib member EDGRMMxx OPTION command
MASTEROVERWRITE operand value when you do not specify a VLPOOL MASTEROVERWRITE
value.