OPTI-TAPE is a product designed to provide VSE/SP and VSE/ESA with virtual tape drive support. VSE/SP or VSE/ESA can use these virtual tape devices just as if they were real tape drives. Reads and writes to a virtual tape drive is intercepted at the channel program level providing a completely transparent interface. Data written or read from these virtual tape drives is re-directed to or from VSAM ESDS files. No changes to application programs or JCL is required.
Virtual tape drives are created by using the VSE IPL ADD command to add virtual (or dummy) tape devices to the VSE PUB (Physical Unit Block) table. When VSE is IPLed, these virtual devices have a 'not operational' status. After OPTI-TAPE has initialized, these virtual tape devices can be attached to the OPTI-TAPE Server using the ATTACH command. After the virtual tape devices have been attached, VSE will think these virtual tape devices are real tape drives available for use.
The OPTI-TAPE virtual tape devices must be defined to VSE as 3422 (9-track tapes) or 3480 (cartridge tapes). Any number of virtual tape devices can be defined to VSE. However, only 28 virtual tape devices can be attached to the OPTI-TAPE Server at the same time.
It is possible to attach real (physically existing) tape drives to the OPTI-TAPE Server. These devices must be defined to VSE as 3410/3422/3430 (9-track) or 3480 (cartridge) devices. After using the ATTACH command to attach a real tape drive to the OPTI-TAPE Server, the device becomes a virtual tape drive. The real device is unusable until the device is detached using the DETACH command.
When OPTI-TAPE is used with BIM-EPIC, CA-EPIC or CA-DYNAM/T, OPTI-TAPE virtual tape drives appear to be part of a virtual robotic tape silo. When the tape management system processes a tape open request, it will always ask the silo (OPTI-TAPE) to mount the requested volume or scatch tape first. If the requested volume or scratch tape is available, OPTI-TAPE will automatically mount it on a virtual tape drive. If the requested volume or scratch tape is not available, normal tape manager processing will continue and the operator will be asked to mount a tape.
Initially the OPTI-TAPE virtual robotic tape silo will contain no virtual tapes. As new tapes are created they are stored as virtual tape files on disk. Operations can use various tape manager reports to determine which volumes will be used during a shift then use the BSOTUTIL IMPORT function to import tapes to the virtual silo. At various times during the day (6:00 PM, End-of-Shift, etc) virtual tapes can be synchronized with the physical tape media using the BSOTUTIL EXPORT and DEPORT functions. The EXPORT function copies a virtual tape to physical tape leaving the virtual tape in the silo. The DEPORT function moves a virtual tape to physical tape deleting the virtual tape from the silo.
Tape files can be manually mounted on a virtual tape drive using the BSOTBMNT (Batch MouNT) program. The BSOTBMNT program reads a mount (NL/SL/DM) command from SYSIPT and executes a special channel program to pass the mount command to the OPTI-TAPE Server for processing.
If you are not using the virtual tape silo interface, tape files can be automatically mounted on a virtual tape drive by the VSE OPEN processing. OPTI-TAPE has a hook in the IJJTOPN (Tape OPEN) routine. When using VSE standard label tape files this routine should automatically allocate new tape file or re-mount old tape files.
If a tape file is already mounted on the virtual tape drive, the automatic mount is bypassed. The previously mounted tape file is used. The tape file will be automatically dismounted by an unload channel command or manually by the DM (DisMount) command.
OPTI-TAPE uses VSAM ESDS datasets to store tape file data. These VSAM ESDS datasets reside in a user selected VSAM catalog. Some user allocate a new VSAM user catalog while others use an existing VSAM user catalog. The VSAM catalog used for VSAM SAM files is a common selection. Once the catalog is selected, a DLBL is added to system standard labels that contains the name of the VSAM catalog to be used.
During installation a model ESDS named OPTI.TAPE.MODEL.ESDS is created in the VSAM catalog selected for use by OPTI-TAPE. The model ESDS specifies the characteristics of the VSAM Clusters that will be allocated by OPTI-TAPE. When OPTI-TAPE allocates a new tape file it invokes IDCAMS to issue a DEFINE CLUSTER command. This command will use the OPTI.TAPE.MODEL.ESDS as a model for cluster characteristics.
OPTI-TAPE VSAM dataset names all begin with the letters 'OT'. The 'OT' is followed by 'NL' indicating Non-Labeled or 'SL' indicating Standard Labeled tape. For 'NL' files a 17 character filename follows the 'OTNL.'. For 'SL' files, the volume serial number, volume sequence number and 17 character filename follow the 'OTSL.'.
Non-Labeled tape files allocated by the automatic mount process have special names. The following format is used by the automatic mount facility for Non-Labeled tape files.
OTNL.id.WRKFL.jobname
Id is the 2 character partition id where job is running and jobname is the 8 character name of the job.
* Non-Labeled tape have the follow form ... OTNL.filenameOTNL.BSILIB.BACKUP OTNL.C1.WRKFL.LIBR * Standard Labeled tapes have the following form ... OTSL.Vvolser.Svseq.filenameOTSL.V056221.S0001.DAILY.TRAN.DATA OTSL.V172588.S0001.MTD.TRAN.HIST
You can specify a filename that contains from 1 through 17 alphanumeric characters, national characters (@, #, and $), and two special characters (the hyphen and the 12-0 overpunch). Names containing more than eight characters must be segmented by periods; one through eight characters may be specified between periods. The first character of any name or name segment must be either an alphabetic or a national character. The last character in the name cannot be a period.
OPTI-TAPE does not support ASCII tape files.
OPTI-TAPE runs under VSE/SP and VSE/ESA. The product uses 64K of system GETVIS. The System GETVIS used is all 31-bit storage on systems with 31-bit system GETVIS available.
To see the benefits of vitual tape support, call 1-800-251-OPTI
today.
We are so confident that OPTI-TAPE will improve your system's
operation that we offer a free, 30-day product evaluation.
© 1996 Barnard Software, Inc.
All names, products, and services mentioned are the
trademarks or registered trademarks of their respective
organizations.