Getting Tape Data Ready for the OS/390 Standard System
One of the biggest challenges—in consolidating the OS/390 North and South systems into a single new OS/390 standard system—is the transfer of user data from over 110,000 tapes to this new system. On the standard system, tape data will be stored on new high-density tapes in a Virtual Storage Manager (VSM) and will be managed by the CA-1 tape management software (currently used by the North system). The VSM will markedly improve performance and reliability of tape data. (Please see the article on VSM later in this issue.)
To use the VSM, tapes in the North and South tape libraries will be copied to the new tape media. Initally, North tapes will move to the VSM. This will occur in one of three ways: 1) as of July 17, all new tape data set allocations to the unitname CTAPE on the North system will automatically be written to the VSM; 2) users can, at any time after July 17, copy tape data, which will be written to the VSM (like other new tape dataset allocations); and 3) on August 1, CIT will begin copying remaining North tapes on an account-by-account basis. When all of the tapes in the North tape library have been copied to virtual tapes, the North tape transition will be complete.
During the transition, the VSM will be shared between the North and standard systems—that is, tapes in the VSM will be accessible from either system. On the South system, the transition of the tape library will be a more involved process: the South tape library is four times larger than the North; there is no data set naming convention for South tapes; and cataloging of tape data is not widely practiced.
People planning to use tapes on the standard system should keep the following conventions in mind:
What Users Can Do Now
To prepare for the transition to the standard system, there are some things that you can do immediately.
Because volume serial numbers for all North tapes will change as they are copied to the VSM, those users who do not reference their tape data through the catalog will need to change their JCL to reflect the new volume serial number (volser). To make the transition to the VSM as painless as possible, North users should catalog their tape data sets now wherever possible. The move to the VSM will be transparent for North users who catalog their tape data. Because cataloged tape data sets will be re-cataloged automatically as they are moved, referencing your data through the catalog will automatically access the new tape media.
When the South tape library is migrated, volume serial numbers (volsers) will change and, in many cases, data sets will need to be re-named. CIT is investigating various strategies for migrating South tapes to minimize this disruption. Although we have no specifics yet about how this process will work, ensuring that new tape data sets are cataloged with valid data set names will lessen the impact of this change.
Although valid disk data set names must begin with the user’s account and registered initials (aaaaiii) followed by a period, no naming convention is currently enforced on the South for tape data. Any data set named beginning with aaaaiii. can be cataloged on the South system and will be accommodated by the standard system naming convention. Therefore, we recommend that new South tape data sets begin with the user’s account and initials and that the user catalog them. It is possible that a naming convention for new tape data sets will be implemented on the South system before the transition to the standard system.
Please check the standard system Web page regularly to see what is happening or join the CIT-OS390-Transition-L listserv list to be notified of changes that are posted on the Web page.
Interface 214 (June 23, 2000)