Draft Document for Review February 7, 2020 3:15 pm 8464ch11_Monitoring.fm For more information, see the  IBM Virtualization Engine TS7700 Series Bulk Volume  Information Retrieval Function User’s Guide , WP101094. Clarification:  Records that are listed in 11.4, “Bul k Volume Information Retrieval” on  page 646 show an initial record of “ 1234567890123 ...”. This record does not exist; it is  provided to improve readability. 11.4.1 BVIR overview The TS7700 converts the format and storage conventions of a tape volume into a standard  file that is managed by a file system within the subsystem. It uses an IBM-standard labeled  tape volume to start a request for information and return the results. By using a standard tape  volume, no special interfaces or access methods are needed for an application to use this  facility. In practice, no specific applications are required because standard IBM utilities, such  as IEBGENER, provide the function that is needed to request and obtain the information. The following steps show how information is obtained by using this function:  1. A single data set with the information request is written to a logical volume. The logical  volume can be any logical volume in the subsystem from which the information is to be  obtained.  A scratch or specific volume request can be used. The data set contains a minimum of two  records and a maximum of three records that specify the type of data that is being  requested. The records are in human-readable form and contain lines of character data.  The data set can be cataloged or uncataloged (although cataloging the data set can make  it easier for subsequent access to the data). On closing the volume, the TS7700 server  recognizes it as a request volume and “primes” the subsystem for the next step. Remember:  Some information that is obtained through this function is specific to the  cluster on which the logical volume is written; for example, cache contents or a  logical-physical volume map. In a TS7700 grid configuration with multiple clusters, use  an MC for the volume to obtain statistics for a specific cluster. Historical statistics for a  multi-cluster grid can be obtained from any of the clusters. 2. The request volume is again mounted, this time as a specific mount. Seeing that the  volume was primed for a data request, the TS7700 appends the requested information to  the data set. The process of obtaining the information and creating the records to append  can take up to several minutes, depending on the request and, from a host’s perspective,  is part of the mount processing time.  After the TS7700 completes appending to the data set, the host is notified that the mount  is complete. The requested data can then be accessed like any other tape data set.  In a job entry subsystem 2 (JES2) environment, the job control language (JCL) to  complete the two steps can be combined into a single job. However, in a JES3  environment, they must be run in separate jobs because the volume is not unmounted and  remounted between job steps in a JES3 environment. After the response data set is written to the request logical volume, that logical volume  functions identically to any other logical volume in the subsystem. Subsequent mount  requests and read accesses to the logical volume do not affect its contents. Write accesses to  the logical volume overwrite its contents. The logical volume can be returned to SCRATCH  status and reused by any application. Chapter 11. Monitoring  647