HP OpenVMS System Management Utilities Reference Manual

If AUTO_DLIGHT_SAV is set to 1, OpenVMS automatically makes the change to and from daylight saving time.

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.

On Alpha and I64 systems, AWSMIN establishes the lowest number of pagelets to which a working set limit can be decreased by automatic adjustment of the working set.

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.

AWSTIME expiration is checked only at quantum end. Reducing its value and not reducing QUANTUM effectively sets the value of AWSTIME equal to the value of QUANTUM.

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.

Note that on VAX systems, virtual balance slots (VBS) can affect the values of BALSETCNT and MAXPROCESSCNT.

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.

Working set growth attempts to alleviate heavy page faulting. To make use of this growth, you must also set the user's WSEXTENT authorization quota to a larger number than the WSQUOTA value.

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.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

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.

Setting the SYSTEM_CHECK parameter to 1 has the effect of setting BUGCHECKFATAL to ON (1).

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.

CHANNELCNT

CHANNELCNT 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.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

CLUSTER_CREDITS

CLUSTER_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.

The default value is currently 32. Unless a system has very constrained memory available, HP recommends that these values not be increased.

CONCEAL_DEVICES

CONCEAL_DEVICES enables or disables the use of concealed devices. By default, this parameter is set to enable concealed devices (1).

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

CPU_POWER_MGMT

On 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_THRSH

On 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_CONTROL

This 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:

Bit Description

0 Enables CRD processing for all systems.

1 Enables scrubbing (rewriting) of the memory location that induced the CRD.

2 Enables page replacement of the pages that exhibit repeated CRD errors.

3 Forces all memory pages to be included in the PFN database. On systems that contain more than 512 megabytes of memory, all memory is mapped by the PFN database by default. This bit allows the mapping to occur on systems with less than 512 megabytes of memory.

Bit	Description
0	Enables CRD processing for all systems.
1	Enables scrubbing (rewriting) of the memory location that induced the CRD.
2	Enables page replacement of the pages that exhibit repeated CRD errors.
3	Forces all memory pages to be included in the PFN database. On systems that contain more than 512 megabytes of memory, all memory is mapped by the PFN database by default. This bit allows the mapping to occur on systems with less than 512 megabytes of memory.

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:

Bit Description

0 Enables CRD processing for all systems.

1 Enables scrubbing (rewriting) of the memory location that induced the CRD.

2 Enables page replacement of the pages that exhibit repeated CRD errors.

3 Forces all memory pages to be included in the PFN database. On systems that contain more than 512 megabytes of memory, all memory is mapped by the PFN database by default. This bit allows the mapping to occur on systems with less than 512 megabytes of memory.

4 Enables extended CRD handling, if available.

5 Enables loading of driver and process for handling server management events. Platform-specific code usually sets this bit if the required hardware and firmware support are available.

6 Disables CRD throttling.

7 Disables System Event Log (SEL) polling.

16-31 Reserved for platform-specific error-handling control.

Bit	Description
0	Enables CRD processing for all systems.
1	Enables scrubbing (rewriting) of the memory location that induced the CRD.
2	Enables page replacement of the pages that exhibit repeated CRD errors.
3	Forces all memory pages to be included in the PFN database. On systems that contain more than 512 megabytes of memory, all memory is mapped by the PFN database by default. This bit allows the mapping to occur on systems with less than 512 megabytes of memory.
4	Enables extended CRD handling, if available.
5	Enables loading of driver and process for handling server management events. Platform-specific code usually sets this bit if the required hardware and firmware support are available.
6	Disables CRD throttling.
7	Disables System Event Log (SEL) polling.
16-31	Reserved for platform-specific error-handling control.

On Alpha and I64 systems, the default setting is 22, which enables scrubbing, page replacement, and extended CRD handling.

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).

Beginning with OpenVMS Version 7.2, CRD_CONTROL can expand the function of CRDENABLE. (See CRD_CONTROL.)

CTLIMGLIM

CTLIMGLIM 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.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

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.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

CWCREPRC_ENABLE

CWCREPRC_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_CTLFLAGS

DCL_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.

Bit Description

Bit 0 If clear (the default), the numeric portion of a system-generated spawned process name is generated randomly. If set, the numeric portion is generated sequentially starting with sequence number 1.
The option of sequential generation is provided for compatibility with OpenVMS versions prior to Version 7.3-1. However, this choice can be very expensive in performance terms because of the mechanism for finding the next available process name. This mechanism attempts to create all process names beginning with sequence number 1 until it finds one that is unused.
Random generation is the preferred choice because it results in a very high probability of finding a unique name on the first try.

Bit 1 Controls the token size used by DCL. If clear (the default), this bit instructs DCL to use the traditional token size. A token cannot exceed 255 characters. If this bit is set, extended tokens are used. Extended tokens are 4000 characters.
Note that if you turn on extended tokens, file specifications can exceed 255 characters, which might require larger structures for parsing file specifications.

Bit 2 If clear (the default), the numeric portion of a system-generated spawned process name has a maximum value of 65535. If set, the numeric portion of the name has a maximum value of 255.
The option of a maximum of 255 is provided for compatibility with OpenVMS versions prior to Version 8.3, when it was the only choice. The larger maximum allows many more unique spawned process names for a given process. For this reason, it is the preferred choice. However, the larger maximum uses two additional characters from the process name, which might make it more difficult to identify users uniquely by looking at their spawned process names. If this is an issue on your system, setting bit 2 might be a better choice.

Bit	Description
Bit 0	If clear (the default), the numeric portion of a system-generated spawned process name is generated randomly. If set, the numeric portion is generated sequentially starting with sequence number 1. The option of sequential generation is provided for compatibility with OpenVMS versions prior to Version 7.3-1. However, this choice can be very expensive in performance terms because of the mechanism for finding the next available process name. This mechanism attempts to create all process names beginning with sequence number 1 until it finds one that is unused. Random generation is the preferred choice because it results in a very high probability of finding a unique name on the first try.
Bit 1	Controls the token size used by DCL. If clear (the default), this bit instructs DCL to use the traditional token size. A token cannot exceed 255 characters. If this bit is set, extended tokens are used. Extended tokens are 4000 characters. Note that if you turn on extended tokens, file specifications can exceed 255 characters, which might require larger structures for parsing file specifications.
Bit 2	If clear (the default), the numeric portion of a system-generated spawned process name has a maximum value of 65535. If set, the numeric portion of the name has a maximum value of 255. The option of a maximum of 255 is provided for compatibility with OpenVMS versions prior to Version 8.3, when it was the only choice. The larger maximum allows many more unique spawned process names for a given process. For this reason, it is the preferred choice. However, the larger maximum uses two additional characters from the process name, which might make it more difficult to identify users uniquely by looking at their spawned process names. If this is an issue on your system, setting bit 2 might be a better choice.

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.

Note

DEFQUEPRI refers to relative queue scheduling priority, not the execution priority of the job.

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:

Option	Description
0	Disable the exit handler functionality with $DELPRC.
4	Execute kernel mode exit handlers.
5 (default)	Execute exec and more privileged mode exit handlers.
6	Execute supervisor and more privileged mode exit handlers.
7	Execute user and more privileged mode exit handlers.

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:

Bit Definition

0 If 1, enable new naming.

1 Must be 0. This bit is reserved for use by HP.

2 If 1, cloned device unit numbers wrap after 9999.

Bit	Definition
0	If 1, enable new naming.
1	Must be 0. This bit is reserved for use by HP.
2	If 1, cloned device unit numbers wrap after 9999.

For more information about port allocation classes, see HP OpenVMS Cluster Systems.

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.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

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.

This special parameter is used by HP and is subject to change. Do not change this parameter unless HP recommends that you do so.

DNVOSI1

DNVOSI1 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.

Setting DR_UNIT_BASE to appropriate, nonoverlapping values on all cluster members that share the same (nonzero) allocation class ensures that no two RAID devices are given the same name.

DUMPBUG

DUMPBUG 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.

Bit Mask Description

0 00000001 0 = Full dump (SYSGEN default). The entire contents of physical memory are written to the dump file.

1 = Selective dump. The contents of memory are written to the dump file selectively to maximize the usefulness of the dump file while conserving disk space.

1 00000002 0 = Minimal console output.

1 = Full console output (includes stack dump, register contents, and so on).

2 00000004 0 = Dump to system disk.

1 = Dump off system disk (DOSD) to an alternate disk. (See the HP OpenVMS System Manager's Manual for details.)

3 (Alpha and I64) ¹ 00000008 0 = Do not compress.

1 = Compress. (See note below.)

4 (Alpha and I64) ² 00000010 0 = Dump shared memory.

1 = Do not dump shared memory. (See note below.)

5 - 14 Reserved for HP use only.

15 (VAX only) ³ 00008000 0 = Disable use of bits 16 - 27.

1 = Enable use of bits 16 - 27.

16 - 27 (VAX only) ² 0FFF0000 Range of DOSD unit numbers.

28 - 31 Reserved for HP use only.

Bit	Mask	Description
0	00000001	0 =	Full dump (SYSGEN default). The entire contents of physical memory are written to the dump file.
		1 =	Selective dump. The contents of memory are written to the dump file selectively to maximize the usefulness of the dump file while conserving disk space.
1	00000002	0 =	Minimal console output.
		1 =	Full console output (includes stack dump, register contents, and so on).
2	00000004	0 =	Dump to system disk.
		1 =	Dump off system disk (DOSD) to an alternate disk. (See the HP OpenVMS System Manager's Manual for details.)
3 (Alpha and I64) ¹	00000008	0 =	Do not compress.
		1 =	Compress. (See note below.)
4 (Alpha and I64) ²	00000010	0 =	Dump shared memory.
		1 =	Do not dump shared memory. (See note below.)
5 - 14			Reserved for HP use only.
15 (VAX only) ³	00008000	0 =	Disable use of bits 16 - 27.
		1 =	Enable use of bits 16 - 27.
16 - 27 (VAX only) ²	0FFF0000		Range of DOSD unit numbers.
28 - 31			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.

Note

On Alpha and I64 systems, you can save space on the system disk and, in the event of a crash, save time recording the system memory, by using the OpenVMS Alpha and I64 dump compression feature. Unless you override the default AUTOGEN calculations (by setting DUMPSTYLE in MODPARAMS.DAT), AUTOGEN uses the following algorithm:

On a system with less than 128 MB of memory, the system sets the DUMPSTYLE to 1 (a raw selective dump) and sizes the dump file appropriately.
On a system with 128 MB of memory or greater, the system sets the DUMPSTYLE to 9 (a compressed selective dump), and creates the dump file at two-thirds the value of the corresponding raw dump.

Examples:

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.

On Alpha and I64 systems, the mask of 00000009 directs the system to compress a selective dump with minimal console output.

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.

If you increase ERLBUFFERPAG_S2, you must either run AUTOGEN or manually increase the size of both the system dump file and the error log dump file.

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.

Contents

Index