Performance and tuning start options

Table 1. Start options that affect performance and tuning. These start options can be displayed as a group with the DISPLAY VTAMOPTS,FUNCTION=PERFTUNE command.
Start option Description
AUTOTI Specifies how often pending automatic logon requests owned by this host are retried
BSCTMOUT The interval in which two general poll failures are allowed for BSC 3270 terminals
CACHETI The amount of time that an APPN search request is remembered to prevent processing the same search again
CDRSCTI The amount of time that dynamic CDRSCs are saved after the last session has ended
CINDXSIZ The maximum size of the ISTCIT and ISTCONVT index tables
DIRSIZE The maximum number of dynamic resources that VTAM® stores in the APPN directory database
DIRTIME The amount of time that a dynamic resource can go unused before it is deleted from the APPN directory database
DLRTCB Specifies the maximum number of task control blocks that VTAM allocates in private storage for various functions
HNTSIZE The maximum size of the host node table used to find element addresses
HPRARB The algorithm that is used for adaptive pacing (not recommended unless you use the default value of RESPMODE)
HPRCLKRT Specifies whether the HPR clock rate runs in standard or adaptive mode. These modes control how reactive VTAM is to the packet loss that occurs on RTP pipes which run over Enterprise Extender.
HPRITMSG Specifies whether VTAM should issue the enhanced version or base version of HPR activation and deactivation messages
HPRPSDLY Specifies the minimum amount of time that VTAM delays prior to initiating path switch logic for an RTP pipe that has an unresponsive partner
HPRPSMSG Specifies whether VTAM should limit the number of HPR path switch messages that are issued
HPRPST The maximum time that VTAM tries a path switch before ending a connection
HPRSESLM Specifies the maximum number of sessions that should be assigned to a single RTP pipe
HSRTSIZE The size of the SRT directory for the network containing the VTAM host node
IOINT The interval after which the VTAM operator is notified of outstanding I/O requests
IOPURGE The interval after which outstanding I/O requests are assumed to be lost and recovery steps are taken
MAXEETST Specifies the maximum number of Enterprise Extender connectivity tests (D NET,EEDIAG,TEST=YES) that are allowed to run concurrently
MAXHNRES Specifies the maximum number of host name resolver requests that are allowed to run concurrently for the D NET,EE or D NET,EEDIAG commands
MAXLOCAT The maximum threshold value to be reached before VTAM suspends sending APPN search requests to an adjacent node
MAXLURU The maximum RU length for LU-LU sessions
MIHTMOUT The interval in which you can adjust the missing interrupt handling interval for channel-to-channel communication
MULTPATH Specifies whether VTAM supports TCP/IP multipath routing for EE connections
MXSAWBUF The maximum number of buffers to use for session awareness data
MXSSCPRU The maximum RU length for all SSCP sessions
NCPBUFSZ The RU size used for loading or dumping a remote NCP
NSRTSIZE Provides an override of OSRTSIZE for a maximum of nine network identifiers
NUMTREES The maximum number of APPN routing trees that can be saved
OSIEVENT Specifies whether VTAM topology notifications are generated for CMIP services events
OSITOPO Specifies whether the VTAM topology agent reports all types of cross domain resources (CDRSCs) to CMIP manager application programs
OSRTSIZE The size of the SRT directory for networks other than the VTAM host node's network
PDTRCBUF The number of buffers to build for a session monitor request
PIUMAXDS A value used to calculate the maximum buffer limit for PIU data space
PMTUD Specifies whether VTAM uses path MTU discovery for IPv4 and IPv6 Enterprise Extender connections
PSRETRY The interval between attempts to switch a rapid transport protocol (RTP) session to a path that can be equal to or better than the current path, and an option to immediately attempt an RTP path switch when a link on this host is activated or changes status
PSWEIGHT The weight comparison between an old route and a newly calculated route before a path switch is attempted
SAWMAXDS A value used to calculate the maximum buffer limit for SAW data space
SAWMXQPK A value used to calculate the number of SAW buffers to queue before packing the buffers
SONLIM The maximum percentage of I/O buffers that can be used for session outage notification RUs
SRCHRED Indicates whether this node enables eliminating and reducing searches for unreachable resources
SRCOUNT The number of search requests that fail before VTAM performs another resource discovery search
SRTIMER The amount of time VTAM does not conduct searches for an unavailable resource
UPDDELAY Specifies the maximum time the VTAM topology agent waits between checking the list of resources in transient states (such as PENDING ACTIVE and PENDING INACTIVE) to determine whether the resources have been in transient states long enough to be sent to the topology manager
VFYRED Specifies whether the node should attempt to perform resource verification reduction
VFYREDTI Specifies the node-wide maximum time interval that a resource's location is not verified
VOSDEACT Can be coded in the VTAM start list, or turned on or off by way of the MODIFY VTAMOPTS command, to cause VTAM to bring a virtual route (VR) down if the VR goes out of sequence
VTAMEAS The size of the table that contains information about sessions with an application program