DASD requirements

IMS 15.2 hardware requirements include several requirements for DASD.

During the binding of the IMS control blocks load modules (specifically during the bind of the IMS VTAM® control blocks load monitoring module), both the binder work data set SYSUT1 and IMS data sets IMS.SDFSRESL and IMS.SDFSJLIB must reside on a device that supports a record size of 18 KB or greater. For all other system libraries and working storage space, any device that is supported by the operating system is allowed.

For IMS database storage, any device that is supported by the operating system is allowed within the capabilities and restrictions of Basic Sequential Access Method (BSAM), Queued Sequential Access Method (QSAM), Overflow Sequential Access Method (OSAM), and Virtual Storage Access Method (VSAM).

The fast replication function of the Database Image Copy 2 utility (DFSUDMT0) requires DASD controllers that support one of the following features:

  • The concurrent-copy feature of DFSMS
  • The FlashCopy® feature of the IBM® Enterprise Storage Server® (ESS)
  • The SnapShot feature of the IBM RAMAC Virtual Array (RVA) storage system

FlashCopy and SnapShot might require microcode from IBM to activate their functionality. Also, the source and target data sets (databases and image copies) must reside on the same ESS or RVA hardware.

The DASD storage requirements for the following items are described in the Program Directory for Information Management System Transaction and Database Servers V15.02.00:

  • SMP/E system entries
  • SMP/E data sets
  • Target libraries
  • Distribution libraries
  • Install process
  • Optional machine-readable material

The following types of data sets can be allocated in the extended addressing space (EAS) of an extended address volume (EAV):

  • GSAM database data sets
  • BPE external trace data sets
  • OSAM database data sets
  • VSAM database data sets
  • Online log data sets (OLDSs), including large OLDS (for example, greater than 64 KB tracks)
  • Write ahead data sets (WADSs)
  • Restart data sets (RDSs)
  • Message queue blocks data sets
  • Long and short message data sets
  • Terminal devices with UNITYPE = SPOOL or DISK
  • RESLIB data sets (IMS.SDFSRESL)
  • MODBLKS data sets for online change (IMS.MODBLKSA and IMS.MODBLKSB)
  • Application control block library (ACBLIB) data sets
  • DBRC RECON data sets (non-PRA)
  • Database Image Copy utility (DFSUDMP0) data sets
  • Database Image Copy 2 utility (DFSUDMT0) data sets
  • Database Change Accumulation utility (DFSUCUM0) data sets
  • Local online change data sets (IMS.MODSTAT)
  • Global online change data sets (IMS.OLCSTAT)
  • Partitioned data set extended (PDSE) data sets (IMS.SDFSJLIB, PGMLIB, SMPLTS, and External Subsystem Attach Facility (ESAF) load libraries)
  • Time-controlled operations (TCO) data sets
  • System log data sets (SLDSs)
  • Recovery log data sets (RLDSs)
  • HALDB Indirect List data sets (ILDSs)
  • IMS Repository data sets
  • MFS map library data sets produced by the MFS Language and Service utilities (IMS.FORMAT)
  • IMS Trace facility external trace data sets
  • IMS Monitor output data sets