VPARS is a product designed to ease testing for the IBM TPF (Transaction Processing Facility) environment, while VTAPE is a tape simulation product that can be used by any operating systems running under VM.

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VPARS   (Virtual PARS)

VPARS is a software enhancement to VM that allows multiple virtual machines to transparently share a TPF (Transaction Processing facilty) database.  Although the TPF records that are modified are maintained on a VPARS database, it appears to each TPF system that it is actually writing to the TPF base. This provides record isolation between virtual machines that are sharing a TPF system. All levels of TPF and ACP are supported by VPARS.

Multi-level (or "concatenated") VPARS databases allow several VPARS databases to be searched for TPF input records. The primary VPARS database is normally a read-write database. The rest are always read-only. Several users can share a read-only VPARS database. This may reduce the number of records required on each user's read/write VPARS database, since a shortload or longload (or any other data) can be written to a database which is then shared read-only among several VPARS users. The primary database can also be a read-only database.

VTAPE   (Virtual Tape)

• Do you run VM on a mainframe?
• Do you have fewer tape drives than your users need, but don't want to buy more?
• Does waiting for tapes to be mounted cause a bottleneck?
• Are you spending time converting MVS or DOS/VSE jobs to use disk files instead of tapes?
• Would you like to test software that uses 3480 and 3490 tape drives, but don't want to buy the drives?
• Are you a software developer who would like an easier way to do faster and more thorough testing on your software that uses tape?
• Would you like to test your tape management and tape backup software much more quickly?
• Do you get tapes from outside sources that have inconsistent labels? Would you like an easy, foolproof way to organize them?
• Do you use tapes only once in a while, and sometimes have trouble locating them?

Virtual Tape is not a tape management system, but a complete implementation of tape drives and tapes in software.