DISPLAY STORUSE pools

The DISPLAY STORUSE command provides a way to remedy a possible shortage of storage space. Table 1 provides a list of storage pools that are displayed using the DISPLAY STORUSE command. Included for each pool is a short description of the pool function and characteristics. These pools are not customer-defined, unlike the buffer pools defined using the VTAM® start options (for example, IOBUF). VTAM allocates and deallocates storage from these pools as needed.

If VTAM is in a storage shortage situation, Table 1 and the output from the DISPLAY STORUSE command can be used to determine where excess storage is being used, enabling you to take appropriate action to remedy the shortage.

Table 1. DISPLAY STORUSE pools
Pool name	Storage location	Description
ACDEB	SYSTEM	A pool element is allocated for every active application.
ACPCB	USER	An element is allocated for every adjacent control point with which this node has an active CP-CP session.
ADJCP	USER	Each pool element defines a single adjacent control point (ADJCP).
ADJNODE	USER	Elements are allocated for each CP-CP session partner to track topology flow status with an adjacent node.
ALPHCD	SYSTEM	Element used by HPDT MPC to manage CSM buffer descriptors. These descriptors represent the storage used for the physical transmission of data over HPDT MPC.
AMU	SYSTEM	Elements are short-lived signals used for intraproduct communication.
ANDCB	USER	One element is allocated the first time a node activates a link supporting CP-CP sessions with a specific adjacent node.
ATGB	USER	An element represents a single T2.1 connection or VR-TG to an adjacent CP.
AUTOLOGN	USER	Elements are used to keep track of autologon relationships.
BFRTRACE	SYSTEM	Elements are used to hold small buffer trace records.
BFRTRFUL	SYSTEM	Elements are used to hold large buffer trace records.
BSBEXT	USER	Elements are allocated for each session using SNA/IP support.
CAB	SYSTEM	One element is allocated for each VCNS connection resulting from a LOGON to a VCNS line (LANs) or from an X.25 OPEN command.
CACHE	USER	Elements are used for caching PCIDs during direct search list processing.
CANT	SYSTEM	One element is allocated for every 64 VCNS X.25 connections for the same LOGON to a VCNS line.
CDAJSCP	USER	Elements are used to define adjacent SSCP entries.
CDRSC	USER	Elements are used to define dynamic CDRSCs and clone CDRSCs.
CFSACCCD	SYSTEM	Coupling facility short-lived common storage pool.
CFSACCCS	SYSTEM	Coupling facility long-lived common storage pool.
CFSACCPD	USER	Coupling facility short-lived private storage pool.
CFSACCPS	USER	Coupling facility long-lived private storage pool.
CFSBUFCD	SYSTEM	Elements are short-lived buffer objects used to manage coupling facility structure data buffers.
CFSBUFCS	SYSTEM	Elements are long-lived buffer objects used to manage coupling facility structure data buffers.
CFSBUFPD	USER	Elements are short-lived buffer objects used to manage coupling facility structure.
CFSBUFPS	USER	Elements are long-lived buffer objects used to manage coupling facility structure.
CFSCSA	SYSTEM	Coupling facility common storage pool.
CFSPRIV	USER	Coupling facility private storage pool.
CMIPPVT	USER	CMIP services allocates most of its buffers from this pool.
CMOBJ	SYSTEM	Elements are used by VTAM connection manager to represent logical connections using HPDT DLCs.
CNSFACUD	SYSTEM	An element is allocated every time a VCNS application asks VTAM to initiate or receive an X.25 call request that will contain facilities or call user data.
CORCB	USER	Elements are used for APPN Locate request correlation.
COS	USER	Elements are used for APPN COS definitions and mode table mappings.
COWE	USER	One element is allocated by the VTAM topology agent for each CMIP operation request the agent processes. The element is freed when the operation ends.
CPRUPE	USER	Elements are request/response unit processing elements used when processing APPN-related requests.
CPWACSA	SYSTEM	An element is allocated when a USS command is entered from the network operator console or from a user terminal. One element from the pool is allocated when an application resource definition specifying SSCPFM=USSNOP is being processed.
CPWAPVT	USER	One element is allocated when a USS command is entered from the network operator console or from a user terminal. One element from the pool is allocated when an application resource definition specifying SSCPFM=USSNOP is being processed.
DCX	SYSTEM	Pool elements are used to maintain data compression information.
DDEL	USER	Elements are used to delay the disconnection of a PU that is defined with the DISCNT=DELAY parameter.
DECB	USER	An element is allocated for each resource in the APPN directory database.
DISKIO	USER	One element is allocated per component performing database hardening. The storage for this pool is allocated below the 16–M line.
DMTSQ	USER	One element is allocated every time a message contained in the message flooding table is issued. The allocated element is freed when the message suppression time expires.
DSERVER	USER	Elements are control blocks and short-term signals related to directory services and interchange nodes.
DSSIB	USER	An element is allocated when a DSRLST is received and freed when the DSRLIST response is sent.
DSUTIL	USER	Elements are used to perform locate search processing.
DYPATH	USER	Elements are path table entries for dynamic PUs.
EEHNMIPD	SYSTEM	An element from this pool is allocated when the SNAMGMT start option is set to YES and a client application connects to the SNA Network Management socket. More elements are allocated when a response is built because of a request from a client application. These additional elements are freed when the response is returned. The original element is freed when either the client or VTAM terminates the connection.
EPTDVT	SYSTEM	Elements are used to contain DLC-specific information.
ERICPOOL	USER	Elements are used while parsing request/response units. When the RU processing completes, the elements are freed.
ERTE	USER	Elements are used to define explicit routes resulting from PATH statements.
FMCB	SYSTEM	Elements are allocated once for each session associated with an application LU (for nonpersistent LU sessions) at session BIND time.
FMCBEXT	SYSTEM	Elements are allocated once for each session associated with an application LU at session BIND time.
FMH5	SYSTEM	One element is allocated for each incoming LU 6.2 conversation request.
GRINS	USER	Elements are used to maintain associations between network resources and generic names.
GWNAJSCP	USER	Elements are: Adjacent SSCP routing tables used to route CDINIT or DSRLST RUs. Elements are freed when the routing completes or fails. Information to determine the gateway NCP to use during session setup.
HIPOOLPS	USER	HPR table used by MNPS
HPRINFO	USER	Elements exist for each RTP connection for which data is being collected by a single performance monitor application.
HSICB	SYSTEM	Elements are allocated once for each APPC session associated with an application LU at session BIND time.
HSQH	SYSTEM	Elements are allocated once for the first of every 107 sessions set up across a VR, at session BIND time.
IOBLOCKL	SYSTEM	Elements in the pool are large DLC-related control blocks (for example a channel-attached NCP). The storage for this pool is fixed and is not paged out of memory by the operating system.
IOBLOCKP	USER	Elements in the pool are large DLC-related control blocks. The storage for this pool is not fixed and can be paged out of memory by the operating system.
IOBLOCKS	SYSTEM	Elements in the pool are small DLC-related control blocks (such as for a channel-attached NCP). The storage for this pool is fixed and is not paged out of memory by the operating system.
IOSIB	USER	Elements are used to process Init_Other (Cross-domain) requests.
IPADDR	USER	Element used to store IP addresses and host names.
ISTENDEL	USER	One element is allocated by a network node for each adjacent served end node or nonnative network node.
ISTSITCB	USER	One element is needed at endpoint and network node server roles for each APPN Search procedure.
ISTTRCEL	USER	Elements are used for the problem determination (PD) trace function of the CNM interface.
KEYTOKEN	SYSTEM	Elements map active cryptographic session key tokens.
LCB	USER	An element is allocated to process locate search requests.
LMTABLE	SYSTEM	Three types of elements come from this pool: One element is allocated for every pair of LUs that have negotiated APPC session limits. The element is allocated when a CNOS with a partner LU is initiated, and freed when the application closes its ACB. An element is used for every application that opens its ACB with APPC=YES. Elements represents current session limits between two LU 6.2s on a particular mode. An element is allocated for every logmode that has been negotiated between two partner LUs. The elements are freed for deletion, or freed when the application closes its ACB.
MARB	USER	Elements are allocated by the VTAM topology agent when the agent sends response data to CMIP services. Elements are freed when the agent is notified that data was received.
MRPOOLPS	USER	Elements contain MNPS RTP information.
NDREC	USER	Elements are used for APPN topology node information.
NIDCB	USER	An element is allocated for each network identifier known to the APPN directory database.
NLPDELPD	USER	Elements contain MNPS NLP entry IDs.
NQDAT	USER	One element is allocated for each network-qualified SRTE.
NSRUL	SYSTEM	Elements are used to process LU 6.2 session activation. NSRUL is used for larger-sized requests.
NSRUS	SYSTEM	Elements are used to process LU 6.2 session activation. NSRUS is used for smaller-sized requests.
NSS	SYSTEM	Elements are used to process LU 6.2 session activation.
OSCB	USER	Elements are used to track outstanding locate search requests.
PAGBLBSB	USER	Elements are allocated for each session using HPR or SNA/IP support.
PAQ	USER	Elements are used to track PLU network addresses for a given LU.
PCDCA	USER	Elements are used for border node PCID caching.
PGIOBLK	SYSTEM	Elements are used when communicating with the 3172 or the OSA.
PLOCB	USER	Elements are used to process locate search requests and replies.
PLUSC	SYSTEM	Elements are used during persistent LU session CLOSE processing.
PLUSDATA	SYSTEM	Elements are allocated once for each persistent LU session associated with an application LU, at session BIND time. An additional element is allocated for each MNPS session at session BIND time.
PLUSFMCB	SYSTEM	Elements are allocated once for each persistent LU session associated with an application LU, at session BIND time.
POAPRIV	USER	One element is allocated for each message destined for a program operator application (POA). If the message requires a reply, a second POAPRIV element is allocated.
POWECOMM	SYSTEM	One element is allocated for every message issued when VTAM is running under a user task.
POWEPRIV	USER	One element is allocated for every message issued when VTAM is running under the VTAM task.
POWMCOMM	SYSTEM	One element is allocated for every single-line message and for every message group when VTAM is running under a user task.
POWMPRIV	USER	One element is allocated for every single-line message and for every message group when VTAM is running under the VTAM task.
PRDLE	SYSTEM	Elements represent random data being used for establishing LU 6.2 sessions with session-level security.
PRIDBLK	USER	Elements map procedure-relation identifier blocks (PRIDs)
PRIDQAB	USER	Elements are used to maintain procedure-relation identifier blocks (PRIDs).
PULURDTE	USER	Elements are used to define dynamic and predefined PUs and LUs.
PVTSTATC	USER	Generic utility pool for large blocks of storage that must be in VTAM private storage for an extended period of time.
PXBFIXED	SYSTEM	Elements are used to expand fixed buffer pools. The storage for this pool is fixed and is not paged out of memory by the operating system.
PXBPAGED	SYSTEM	Elements are used to expand pageable buffer pools.
RAB	SYSTEM	One element is allocated for each APPC conversation.
RAQ	USER	Elements are used to queue requests when a usable network address is not available and an RNAA must be sent.
RIBRANT	SYSTEM	One element is allocated for each LOGON of a VCNS application to a VCNS line, plus one extra element for every 16 LOGONs.
RPMNPSPS	USER	RTP elements used by MNPS
RTPINFO	USER	Contains a number of different elements, all of which are used for HPR. Both the RTP and RCM components use this pool.
RUCON	USER	One element is allocated each time a DISPLAY ROUTE,TEST=YES command is issued. After 168 elements have been allocated, VTAM will delete any elements that have not been used for more than 30 minutes.
RUPECOMM	SYSTEM	Elements are allocated from this pool to process request/response units (RUs) when execution is taking place in the VTAM address space.
RUPEPRIV	USER	Elements are allocated from this pool to process request/response units (RUs) when execution is taking place in a non-VTAM address space.
SAB	SYSTEM	One element is allocated for each APPC session.
SCCB	USER	Elements are used to perform search concentration.
SIB	USER	One element is allocated for each LU-LU session.
SIBEXT	USER	One or two elements are allocated for each cross-network session. The elements are freed when the session ends.
SIBIX	USER	One element is allocated during session initiation. The element is freed when the session becomes active.
SLD	SYSTEM	Elements are allocated to process APPCCMD CONTROL=OPRCNTL,QUALIFY=DISPLAY macro instructions, including those issued from the operator console.
SLENT	USER	A pool element is allocated when a CPSVCMG session is activated between an end node and serving network node, or for any CP SNASVCMG sessions that VTAM management services transport activates.
SPTPOOL	SYSTEM	Holds all of the SPTAEs for the associated pools.
SRTE	USER	Elements are entries in the symbol resolution table.
SSCPFMCB	USER	One element is allocated for each SSCP-PU or SSCP-LU session.
STB	USER	Elements store information concerning a T2.1 adjacent link station that an independent LU is using for session connectivity.
TCPIOCD	SYSTEM	TCP/IP IO buffer pool used for QDIO.
TGP	USER	One element is created for each TG profile (TGP) entry.
TGREC	USER	Elements are used for APPN topology TG information.
TIPACX	SYSTEM	Elements contain control information to support HPDT services. The storage for this pool is fixed and is not paged out of memory by the operating system.
TREEBLD	USER	Elements are used for APPN routing tree construction and maintenance.
TRSINFO	USER	Elements are used for topology broadcast lists (for use during topology database update broadcasting) and endpoint TG vector information (during route calculation).
UECB	SYSTEM	One element is allocated each time a user exit is to be scheduled.
UNSOL	USER	An element is allocated for every adjacent control point with which this node has an active CP-CP session.
UTILCSAL	SYSTEM	Generic utility pool for large blocks of storage that must be in CSA.
UTILCSAS	SYSTEM	Generic utility pool for small blocks of storage that must be in CSA.
UTILPVTL	USER	Generic utility pool for large blocks of storage that must be in private storage.
UTILPVTS	USER	Generic utility pool for small blocks of storage that must be in private storage.
UVRPL	USER	One element is allocated each time a user exit is to be scheduled.
VRDCB	SYSTEM	An element exists for each virtual route for which data is being collected by at least one performance monitor application.
VRPL	SYSTEM	Elements are VTAM copy of an application request parameter list (RPL). Elements are also used for BINDs and other RUs received from the network.
VRRSB	USER	An element exists for each virtual route for which data is being collected by a single performance monitor application.
WAR	USER	Elements represent autologon session originators (OLU-SLU) waiting for the availability of a required PU resource.
WREEID	USER	Elements are used to suspend and resume VTAM processes.
XNINFO	USER	Elements are used for search processing.
Note: Unless otherwise specified: All pool storage is pageable and can be paged out of memory by the operating system. All pool storage can be located above or below the 16M line. Some of the pools above are defined to be associated with certain VTAM tasks. Pools are associated with VTAM tasks to improve performance during storage allocation. The DISPLAY STORUSE command will not display usage for the associated pools. The total storage used does account for storage allocated by these pools