The extended Mass Storage System support is packaged as two items although both must be present for full MSS support. Both are packaged
and distributed along with the Release 6 base package for 3850 support: • to the control program component of V8/370 such that YM/370 recognizes and utilizes the SSs for online D1SD allocation. • The M5S communicator program which runs in a virtual machine under OS/VS1 or MVS and communicates with both the control program and the mass storage control (SSC) of the MS5, so that orders are
passed from the control program to the MSC. SRL AND PROGRAM LOGIC PUBLICATIONS The following publications contain information on VM/370 support of the 3850 Mass Storage System (MSS): GC20-1800 Introduction GC20-1801 Planning and System Generation Guide GC20-1806 Operator's Guide GC20-1807 System Program.er's Guide GC20-1808 System Messages GC20-1821 Operating Systems in a virtual Machine SY20-0882 Service Routines Program Logic Manual 5Y20-0884 Data Areas and Control Block Logic 5Y20-0886 System Logic and Problem Determination Guide, Yo1. 1 Section Su.mary of Changes to the Syste. 1-11

VM/370 Measurement Facility (Monitor)
The V8/370 measurement facility (monitor)
and recording capabilties of the monitor.
extends the data collection
These capabilities include: • The gathering of additional devices, storage. processing.
data related to the utilization of
alternate
T ... , - paths, and • The capability for the system programmer to select devices for which
seek infor.ation is to be collected • Extensions to the capability of the system programmer to specify when
the V8/370 menitor is to close the monitor spool file
The following modifications have been made to the V8/370 measurement facility:
CHANNEL AND DEVICE UTILIZATION The V8/370 monitor gathers additional data related to the utilization of
channels, contrel units, and devices. A high frequency sampler gathers
utilization data which itself is sampled by the tASTAP class of data
collection. STORAGE UTILIZATION During CP initialization, V8/370 informs the systea operator of the
partitioning of storage used by V8/370. The message sent to the
operator specifies the size of the nucleus, the size of the initial dynamic area, the size of the trace table, and the amount of available
free storage. The V8/370 monitor also records this information in the
header record of the Y8/370 monitor spool file.
ALTERNATE PATH STATISTICS The Y8/370 monitor now gathers data that provides information about the
use of alternate I/O paths. The monitor collects and records: • The number of times an SIO instruction was issued on an alternate
path • The number of times a related I/O block was queued or dequeued • The number of times a related I/O block stack was depleted
1-12 IB8 Y8/370 Release 6 Guide