EMC Symmetrix DMX-3, Product Manual, Page: 230 / 326

230 EMC Symmetrix DMX-3 Product Guide
Mainframe Features and Support
Multi-Path Lock
Facility/Concurrent
Access Symmetrix systems support the IBM Multi-Path Lock
Facility/Concurrent Access (MPLF/CA) feature for use with
Transaction Processing Facility (TPF) host operating system
environments. MPLF/CA allows multiple concurrent I/O requests to
the same logical device from multiple TPF mainframes.
Note: Contact your local EMC Sales Representative for availability of TPF
support.
The Symmetrix system maintains the names and status of logical
locks currently in use and responds to requests to obtain or release a
lock. This allows multiple hosts to share DASD through multiple
paths in an active OnLine Transaction Processing (OLTP)
environment while maintaining data integrity. MPLF/CA is an
enhancement and replacement for the Extended Limited Lock
Facility (ELLF) and the Limited Lock Facility (LLF). The Symmetrix
system must be emulating the 3990-6, 2105, or 2107 storage control
and running Enginuity supporting the MPLF/CA feature.
MultiSubsystem
Imaging The Symmetrix DMX systems support multiple z/OS environments
by providing maximum connectivity through the use of its 3990-6,
2105, or 2107 emulation modes and the Hypervolume Extension
feature. The Symmetrix systems support up to 250 SubSystem
IDentifiers (SSIDs) with up to 256 devices per SSID.
Sequential Data
Striping
The Symmetrix DMX systems are fully compatible with the IBM
Sequential Data Striping function for 3990-6, 2105, or 2107 storage
control with Extended Platform. Sequential Data Striping provides
faster batch execution on large I/O-bound sequential processing
requests by allowing I/O operations to be managed in parallel across
as many as 16 devices. Sequential Data Striping is available only in
z/OS with DFSMS environments.
The Symmetrix system must be emulating 3990-6, 2105, or 2107
storage control and running Enginuity supporting this feature.
Additionally, the Symmetrix system must have SMS-managed
volumes.
Partitioned Data Set
(PDS) Assist The Symmetrix DMX systems support the IBM Partitioned Data Set
(PDS) Search Assist feature for 3990-6, 2105, 2107, and z/OS storage
control with Extended Platform. PDS Assist improves performance
on large, heavily used partitioned datasets by modifying the
directory search process. PDS Assist is automatically invoked with