HP OpenVMS Systems Documentation
HP OpenVMS System Management Utilities Reference Manual
AWSMIN (D)On VAX systems, AWSMIN establishes the lowest number of pages to which a working set limit can be decreased by automatic working set adjustment.
AWSTIME (D)AWSTIME specifies the minimum amount of processor time that must elapse for the system to collect a significant sample of a working set's page fault rate. The time is expressed in units of 10 milliseconds. The default value of 20, for example, is 200 milliseconds.
Some application configurations that have a large number of memory-intensive processes may benefit if the value is reduced. The value can be as low as 4.
BALSETCNT (A,G,D,M)BALSETCNT sets the number of balance set slots in the system page table. Each memory-resident working set requires one balance set slot.
You can monitor the active system with the DCL command SHOW MEMORY or the MONITOR PROCESSES command of the Monitor utility to determine the actual maximum number of working sets in memory. If this number is significantly lower than the value of BALSETCNT, this parameter value could be lowered. If all balance set slots are being used, raise the value of BALSETCNT.
Never set BALSETCNT to a value higher than 2 less than MAXPROCESSCNT. If physical memory is a significant system constraint, consider lowering this value even further. However, if your system runs with a number of processes nearly equal to MAXPROCESSCNT, lowering BALSETCNT forces swapping to occur, which can affect system performance.
BALSETCNT is no longer a strict setting of the number of processes that might be resident in memory. The swapper tries to reduce the number of resident processes down to BALSETCNT. However, if the total number of active processes and processes that have disabled swapping exceeds BALSETCNT, the swapper does not force processes out of memory just to meet the BALSETCNT setting.
BORROWLIM (A,D,M)BORROWLIM defines the minimum number of pages required on the free-page list before the system permits process growth beyond the working set quota (WSQUOTA) for the process. This parameter should always be greater than FREELIM.
This parameter allows a process to grow beyond the value set by the working set quota (WSQUOTA) to the working set quota extent (WSEXTENT) on a system that has a substantial memory on the free-page list. This automatic working set adjustment also depends upon the values of parameters WSINC, PFRATH, and AWSTIME.
BREAKPOINTS (D)If XDELTA is loaded, BREAKPOINTS enables additional built-in calls for XDELTA during the boot sequence. The breakpoints that are enabled may change from release to release of OpenVMS.
BUGCHECKFATAL (D)BUGCHECKFATAL enables or disables the conversion of nonfatal bugchecks into fatal bugchecks. The system must be rebooted on a fatal bugcheck. A nonfatal bugcheck places an entry only in the error log and deletes the corresponding process.
This parameter should normally be OFF (0); you should set it ON (1) only when the executive is being debugged.
BUGREBOOT (D)BUGREBOOT enables or disables automatic rebooting of the system if a fatal bugcheck occurs. This parameter should normally be on (1); set it off (0) only when the executive is being debugged.
CHANNELCNTCHANNELCNT specifies the maximum number of I/O channels available to processes and to the system. The FILLM quota can be used to reduce the maximum number of I/O channels for a process. A process with a FILLM quota larger than CHANNELCNT is nevertheless limited to the maximum number of I/O channels specified by CHANNELCNT.
CHECK_CLUSTER(VAX only) CHECK_CLUSTER is the VAXCLUSTER parameter sanity check. When CHECK_CLUSTER is set to 1, SYSBOOT outputs a warning message and forces a conversational boot if it detects that the VAXCLUSTER parameter is set to 0.
CLASS_PROT (D)CLASS_PROT performs the nondiscretionary classification checks. CLASS_PROT is also checked by XQP to determine if a classification block should be added to the header of any created files.
CLISYMTBL (D)CLISYMTBL sets the size of the command interpreter symbol table, which controls the number of DCL symbols that can be created.
CLOCK_INTERVAL(VAX only) CLOCK_INTERVAL sets the number of microseconds between the hardware interval timer clock interrupts. It has no effect on processors that have implemented only the subset interval clock registers.
CLUSTER_CREDITSCLUSTER_CREDITS specifies the number of per-connection buffers a node allocates to receiving VMS$VAXcluster communications.
If the SHOW CLUSTER command displays a high number of credit waits for the VMS$VAXcluster connection, you might consider increasing the value of CLUSTER_CREDITS on the other node. However, in large cluster configurations, setting this value unnecessarily high consumes a large quantity of nonpaged pool. Each receive buffer is at least SCSMAXMSG bytes in size but might be substantially larger depending on the underlying transport.
It is not required for all nodes in the cluster to have the same value for CLUSTER_CREDITS.
CONCEAL_DEVICESCONCEAL_DEVICES enables or disables the use of concealed devices. By default, this parameter is set to enable concealed devices (1).
CPU_POWER_MGMTOn I64 systems, a CPU can be placed in "low-power mode" when it is idle. This minimizes power consumption, thereby reducing energy costs for the system. Beginning in Version 8.2-1, OpenVMS I64 supports this feature based on the settings of two system parameters: CPU_POWER_MGMT and CPU_POWER_THRSH.
A value of 1 for CPU_POWER_MGMT means on (the default); a value of 0 means off. Whenever the CPU_POWER_THRSH parameter value is exceeded, the operating system places an I64 processor in low-power mode if it is idle. OpenVMS I64 does this only if CPU_POWER_MGMT is on. A CPU returns to normal power when it receives an interrupt.
CPU_POWER_THRSHOn I64 systems, CPU_POWER_THRSH is a parameter expressed as a percentage. OpenVMS I64 monitors how active each CPU is over a fixed time period. If CPU_POWER_MGMT is on and a CPU is idle for a period of time indicated by CPU_POWER_THRSH, the CPU is placed in a low-power mode if it is idle. A CPU returns to normal power when it receives an interrupt.
For systems supporting real-time operations that require quick response time, HP recommends that this feature be turned off. Use of this feature can result in a small performance degradation.
For more information, see the Intel IA-64 Architecture Software Developer's Manual, Volume 2: IA-64 System Architecture.
CRD_CONTROLThis special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.
On VAX systems, CRD_CONTROL serves the function of CRDENABLE in earlier releases. On Alpha and I64 systems, CRD_CONTROL can be used to expand the function defined by CRDENABLE.
CRD_CONTROL is a bit mask for corrected read data (CRD) soft error control flags. These flags control the use of CRDERROR routines.
On VAX systems, the following bits are defined:
Default values are different for VAX, Alpha, and I64 systems. On VAX systems, the default is 7, which enables CRD processing, scrubbing, and page replacement.
On Alpha and I64 systems, the following bits are defined:
CRDENABLE(Alpha and I64) CRDENABLE enables or disables detection and logging of memory-corrected read data (ECC) errors. This parameter should normally be set to (1).
CTLIMGLIMCTLIMGLIM specifies the size of the default image I/O segment; that is channel table and initial buffer pool for image-related file and RMS I/O.
CTLPAGES (A)CTLPAGES specifies the size of P1 pool. CTLPAGES is automatically changed only when the process logical name table, DCL symbols, or some layered products require an increase in the size of the P1 pool area.
CWCREPRC_ENABLECWCREPRC_ENABLE controls whether an unprivileged user can create a process on another OpenVMS Cluster node. The default value of 1 allows an unprivileged user to create a detached process with the same UIC on another node. A value of 0 requires that a user have DETACH or CMKRNL privilege to create a process on another node.
DBGTK_SCRATCH(Alpha and I64) DBGTK_SCRATCH specifies how many pages of memory are allocated for the remote debugger. This memory is allocated only if remote debugging is enabled with the 8000 boot flag. Normally, the default value is adequate, but if the remote debugger issues an error message, you should increase this value. See Writing OpenVMS Alpha Device Drivers in C (Margie Sherlock and Lenny S. Szubowicz, Digital Press, 1996).
DCL_CTLFLAGSDCL_CTLFLAGS is a bit mask that alters default behavior for certain DCL-related functions on a systemwide basis. However, the default values satisfy the needs of most systems.
Bits 0 and 2 control the formulation of system-generated process names for processes created using the SPAWN command or LIB$SPAWN library routine. They are provided for compatibility with behavior of prior OpenVMS versions. Note that you can eliminate the use of system-generated names by supplying your own process names.
Bit 1 controls the token size used by DCL.
DCL_CTLFLAGS bits are described in the following table.
DEADLOCK_WAIT (D)DEADLOCK_WAIT defines the number of seconds that a lock request must wait before the system initiates a deadlock search on behalf of that lock. Setting DEADLOCK_WAIT to zero disables deadlock checking. Setting DEADLOCK_WAIT to a value greater than zero and less than the default setting provides faster detection of deadlocks but requires more CPU usage.
The DEADLOCK_WAIT value is expressed in seconds; therefore, the smallest value you can set is 1 second. Beginning in HP OpenVMS Version 8.3, a subsecond deadlock wait time, which is set in the system service $SET_PROCESS_PROPERTIESW item code $PPROP$C_DEADLOCK_WAIT, overrides DEADLOCK_WAIT. For more information, see the $SET_PROCESS_PROPERTIESW system service in HP OpenVMS System Services Reference Manual.
DEFMBXBUFQUO (D)DEFMBXBUFQUO sets the default for the mailbox buffer quota size in bytes when this value is not specified in a Create Mailbox ($CREMBX) system service call.
DEFMBXMXMSG (D)DEFMBXMXMSG sets the default for the mailbox maximum message size in bytes when this value is not specified in a Create Mailbox ($CREMBX) system service call.
DEFPRI (D)DEFPRI sets the base default priority for processes.
DEFQUEPRI (D)DEFQUEPRI establishes the scheduling priority for jobs entered in batch and output (printer, server, and terminal) queues when no explicit scheduling priority is specified by the submitter. The value of this parameter can range from 0 to 255; the default value is 100.
The value of DEFQUEPRI should be less than or equal to MAXQUEPRI.
DELPRC_EXIT (D)DELPRC_EXIT can be used to control $DELPRC system service options that call exit handlers prior to final cleanup and deletion of a process. The following table describes these options:
DEVICE_NAMING(Alpha and I64) DEVICE_NAMING is a bit mask indicating whether port allocation classes are used in forming SCSI device names.
Following is the bit definition:
DISABLE_UPCALLS (D)DISABLE_UPCALLS is primarily a debugging aid. It allows the system manager to disable threads upcalls of specific types for the entire system. The value is a bit mask, with the bits corresponding to the upcall types. The upcall types are defined in the definition macro $TMCDEF.
DISK_QUORUM (D)The DISK_QUORUM parameter is the name of an optional quorum disk in ASCII. ASCII spaces indicate that no quorum disk is being used.
DLCKEXTRASTK(VAX only) DLCKEXTRASTK specifies the amount of extra interrupt stack (in bytes) to leave when doing a deadlock search.
This parameter is not used on Alpha or I64 systems.
DNVOSI1DNVOSI1 is reserved to DECnet-Plus for OpenVMS. This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.
DORMANTWAIT (D)DORMANTWAIT specifies, in seconds, the amount of time that can elapse without a significant event before the system treats a low-priority computable process as a DORMANT process for scheduling purposes. (A low-priority process is a non real-time process whose current priority is equal to or less than the value specified by the system parameter DEFPRI [default=4].) After SUSP (suspended) processes, DORMANT processes are the most likely candidates for memory reclamation by the swapper.
Increasing the value of DORMANTWAIT can increase the interval that a low priority process blocks a high priority process if that low priority process is holding a lock or resource that the higher priority process is waiting for.
DR_UNIT_BASE (G)(Alpha only) DR_UNIT_BASE specifies the base value from which unit numbers for DR devices (DIGITAL StorageWorks RAID Array 200 Family logical RAID drives) are counted.
DR_UNIT_BASE provides a way for unique RAID device numbers to be generated. DR devices are numbered starting with the value of DR_UNIT_BASE and then counting from there. For example, setting DR_UNIT_BASE to 10 produces device names such as $1$DRA10, $1$DRA11, and so on.
DUMPBUGDUMPBUG enables (1) or disables (0) the writing of error log buffers and memory contents to SYS$SYSTEM:SYSDUMP.DMP when a fatal bugcheck occurs. This parameter should be off (0) only when the executive is being debugged.
DUMPSTYLE (A,D)DUMPSTYLE specifies the method of writing system dumps.
DUMPSTYLE is a 32-bit mask, with the following bits defined. Each bit can be set independently. The value of the system parameter is the sum of the values of the bits that have been set. Remaining or undefined values are reserved for HP use only.
1VAX systems do not support dump compression.
2VAX systems do not support shared memory.
3Specific to VAX 7000s.
If you plan to enable the Volume Shadowing minimerge feature on an Alpha or I64 system disk, be sure to specify DOSD to an alternate disk.
The mask of 00000006 directs the system to send a full dump, with full console output, off the system disk (to the alternate disk).
For a VAX 7000, a mask of 00098006 directs the system to send a full dump with full console output to the DOSD whose unit number is 9.
ERLBUFFERPAG_S2 (A on Alpha and I64)ERLBUFFERPAG_S2 specifies the amount of S2 space memory to allocate for each S2 space error log buffer requested by the ERRORLOGBUFF_S2 parameter.
ERLBUFFERPAGES (A on Alpha and I64)ERLBUFFERPAGES specifies the amount of S0 space memory to allocate for each S0 space error log buffer requested by the ERRORLOGBUFFERS parameter.
ERRORLOGBUFF_S2 (A on Alpha and I64)ERRORLOGBUFF_S2 specifies the number of S2 space error log buffers reserved for system error log entries. Each buffer is ERLBUFFERPAG_S2 in length. If ERRORLOGBUFF_S2 is too low, messages might not be written to the error log file. If it is too high, the buffers can consume unnecessary physical pages.