The PREFIX controls what is written on the internal label as a dataset name.
>From the 'help def devclass' output: PREFIX Specifies the high level qualifier of the data set name that the server writes into the sequential access media labels. For each sequential access volume assigned to this device class, the server uses this prefix to create the data set name. This parameter is optional. The default value is ADSM. The maximum length of this prefix is 8 more... (<ENTER> to continue, 'C' to cancel) characters. If you have already established a media label naming convention that supports your current management system, use a volume prefix that conforms to your naming conventions. Values specified for this parameter must meet the following conditions: o The value is to be made up of qualifiers, which can contain up to 8 characters (including periods). For example, the following value would be acceptable: AB.CD2.E o The qualifiers must be separated by a single period. o The first letter of each qualifier must be alphabetical or national (@,#,$), followed by alphabetical, national, hyphen, or numeric characters. An example of a tape volume data set name using the default prefix is ADSM.BFS. >>> [EMAIL PROTECTED] 02/14/06 7:03 AM >>> Hi there, We have the venerable IBM 3584, and I created a devclass "dbtape" with a prefix of "TDB". I then printed a set of barcodes TDB001L2 ... TDB015L2. Checked in the tapes as scratch, labels=b, etc. q libvol shows them. When I went to backup db devc=dbtape, it picked a scratch tape with a different prefix. Does the PREFIX option actually do anything on an LTO library? What I want is to use the PREFIX attribute to control which tapes can be used for a database backup, rather than maintaining a file of appropriate volume labels. TIA, --Jim