## Tapes that are created on z/OS and read into z/TPF 

Tapes that are created on z/OS and read into z/TPF use the same z/OS process for creating tapes. Now, when z/TPF wants to read this z/OS-created tape, it does a specific mount of the tape virtual server network (VSN) into a z/TPF-allocated drive by using the z/TPF ( ztplf ) commands. 

## TS7700 performance for z/TPF 

You can use the normal z/TPF Data Collection and Reduction reports that summarize read and write activity to the z/TPF-allocated drive. For TS7700 specific performance, use the normal TS7700 statistics that are offloaded to z/OS through the TS7700 Bulk Volume Information Retrieval (BVIR) function. 

## Support of large virtual volumes for z/TPF (2 GB and 4 GB) 

z/TPF does not use functions, such as Data Class (DC), to control the logical volume size for specific mounts. User exits enable you to set construct names for a volume. If you are not using the user exits, you can set the default size through the TS7700 Management Interface (MI) during logical volume insertion, as described in “Implementing Outboard Policy Management for z/TPF” on page 827. 

Consider the following information when you implement a TS7700 in a TPF environment: 

GLYPH<SM590000> Reserving a tape category does not prevent another host from using that category. You are responsible for monitoring the use of reserved categories. 

GLYPH<SM590000> Automatic insert processing is not provided in z/TPF. 

GLYPH<SM590000> Currently, no IBM TMS is available for z/TPF. 

Advanced Policy Management is supported in z/TPF through a user exit. The exit is called any time that a volume is loaded into a drive. Then, the user can specify, through the z/TPF user exit, whether the volume inherits the attributes of an existing volume by using the clone VOLSER attribute. Or, the code can elect to specifically set any or all of the Storage Group (SG), Management Class (MC), Storage Class (SC), or DC construct names. If the exit is not coded, the volume attributes remain unchanged because the volume is used by z/TPF. 

For z/TPF V1.1, APAR PJ31394 is required for this support. 

## Library interface 

z/TPF features only one operator interface with the TS7700, which is a z/TPF functional message that is called ZTPLF . The various ZTPLF  functions enable the operator to manipulate the tapes in the library as operational procedures require. These functions include Reserve, Release, Move, Query, Load, Unload, and Fill. For more information, see IBM TotalStorage 3494 Tape Library: A Practical Guide to Tape Drives and Tape Automation , SG24-4632. 

## Control data sets 

The z/TPF host does not keep a record of the volumes in the TS7700 tape library or manages the tape volumes in it. You can use the QUERY  command to obtain information about the tape volumes that are held in the TS3500/3952 Tape Library. 

## Service information message and media information message presentation 

Service information messages (SIMs) and media information messages (MIMs) report hardware-related problems to the operating system. 

