OpenVMS System Management Utilities Reference Manual

Document revision date: 19 July 1999

OpenVMS System Management Utilities Reference Manual

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You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_DFMBFSDK (A,D)

RMS_DFMBFSDK establishes the default RMS multibuffer count for sequential disk operations. This value defines the number of I/O buffers that RMS allocates for sequential disk files.

The default value is usually adequate. However, if read-ahead or write-behind operations are used, a larger number improves performance.

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_DFMBFSMT (A,D)

RMS_DFMBFSMT establishes the default RMS multibuffer count for magnetic tape operations. This value defines the number of I/O buffers that RMS allocates for magnetic tape files.

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_DFMBFSUR (A,D)

RMS_DFMBFSUR establishes the default multibuffer count for unit record devices.

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_DFNBC (A,D)

RMS_DFNBC specifies a default block count for network access to remote, sequential, indexed sequential, and relative files.

The network block count value represents the number of blocks that RMS is prepared to allocate for the I/O buffers used to transmit and receive data. The buffer size used for remote file access, however, is the result of a negotiation between RMS and the remote file access listener (FAL). The buffer size chosen is the smaller of the two sizes presented.

Thus, RMS_DFNBC places an upper limit on the network buffer size that is used. It also places an upper limit on the largest record that can be transferred to or from a remote file. In other words, the largest record that can be transferred must be less than or equal to RMS_DFNBC multiplied by 512 bytes.

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_EXTEND_SIZE (D)

RMS_EXTEND_SIZE specifies the number of blocks by which files are extended as they are written. This number should be chosen to balance the amount of extra disk space wasted at the ends of each file against the performance improvement provided by making large extents infrequently.

When small disk quotas are used, specify a small number such as the disk cluster size to prevent the user's disk quota from being consumed. If the value of 0 is used, RMS allocates large extents and truncates the file back to its actual usage when it closes.

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_FILEPROT

RMS_FILEPROT determines the default file protection for system processes such as those that create the error log, operator log, and job controller. It also determines default file protection for processes created by the job controller (all interactive and batch processes).

Because a process always inherits its default file protection from its creator process, RMS_FILEPROT determines default file protection only for users who do not execute the DCL command SET PROTECTION/DEFAULT in their login command procedures or during interactive sessions.

The protection is expressed as a mask. (See the discussion of the $CRMPSC system service in the OpenVMS System Services Reference Manual for more information about specifying protection masks.) By default, the mask is 64000 (decimal) or FA00 (hexadecimal), which represents the following protection:

(S:RWED,O:RWED,G:RE,W:)

You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_DEFAULT.

RMS_PROLOGUE (D)

RMS_PROLOGUE specifies the default prologue RMS uses to create indexed files. The default value 0 specifies that RMS should determine the prologue based on characteristics of the file. A value of 2 specifies Prologue 2 or Prologue 1, and 3 specifies Prologue 3. The RMS prologues are described in the OpenVMS Record Management Services Reference Manual.

RSRVPAGCNT

RSRVPAGCNT sets the number of pages that are reserved and escrowed for the current process page file.

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

S0_PAGING

S0_PAGING controls paging of system code:

Setting bit 0 disables paging of all Exec code and data.
Setting bit 1 disables paging of all RMS code and data.

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

S2_SIZE

(Alpha only) S2_SIZE is the number of megabytes to reserve for S2 space (does not include size required for Spiralog file cache).

SA_APP

SA_APP is a special parameter reserved for Compaq use only.

SAVEDUMP

If the dump file is saved in the page file, SAVEDUMP specifies whether the page file is saved until the dump file is analyzed. The default value 0 specifies that the page file should not be retained. A value of 1 specifies that the dump written to the page file should be retained until either copied or released using the SDA utility.

SBIERRENABLE

(VAX only) This parameter enables (1) SBI error detection and logging.

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

SCH_CTLFLAGS (D)

(VAX only) This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so.

The vector scheduling subsystem presently provides an enlarged quantum to processes requiring vector capability. Customer sites can disable vector quantum adjustment by setting bit NO_VEC_QUANTADJ (bit 9) in the system parameter SCH_CTLFLAGS. Setting this bit causes the scheduler to treat the vector processes and scalar processes uniformly. However, doing so results in more frequent vector context switches when the number of vector processes exceeds the number of vector processors in the system.

SCSBUFFCNT (A,F,G)

On VAX systems, SCSBUFFCNT is the number of buffer descriptors configured for all SCA. If an SCA device is not configured on your system, this parameter is ignored. Generally speaking, each data transfer needs a buffer descriptor and thus the number of buffer descriptors can be a limit on the number of possible simultaneous I/Os. Various performance monitors report when a system is out of buffer descriptors for a given workload which is an indication that a larger value for SCSBUFFCNT is worth considering. Note that AUTOGEN provides feedback for this parameter on VAX systems only.

On Alpha systems, the SCS buffers are allocated as needed, and SCSBUFFCNT is reserved for Compaq use only.

SCSCONNCNT

Beginning with OpenVMS Version 7.2, this parameter is obsolete. SCS connections are now allocated and expanded only as needed, up to a limit of 65,000.

SCSFLOWCUSH (D)

Specifies the lower limit for receive buffers at which point SCS starts to notify the remote SCS of new receive buffers. For each connection, SCS tracks the number of receive buffers available. SCS communicates this number to the SCS at the remote end of the connection. However, SCS does not need to do this for each new receive buffer added. Instead, SCS notifies the remote SCS of new receive buffers if the number of receive buffers falls as low as the SCSFLOWCUSH value.

The default value is adequate on most systems. If an SCA port is not configured on your system, this parameter is ignored.

SCSI_NOAUTO (D)

(VAX only) This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so.

SCSI_NOAUTO prevents the loading of a disk or tape SCSI class driver for any given device ID in a configuration that includes a SCSI third-party device. The SCSI_NOAUTO system parameter stores a bit mask of 32 bits, where the low-order byte corresponds to the first SCSI bus (PKA0), the second byte corresponds to the second SCSI bus (PKB0), and so on, as follows:

#31 24 23 16 15 8 7 0 +-------+-------+-------+-------+ | D | C | B | A | +-------+-------+-------+-------+

For each SCSI bus, setting the low-order bit inhibits automatic configuration of the device with SCSI device ID 0; setting the second low-order bit inhibits automatic configuration of the device with SCSI device ID 1, and so forth. For instance, the value 00002000_16 prevents the device with SCSI ID 5 on the bus identified by SCSI port ID B from being configured. By default, all the bits in the mask are cleared, allowing all devices to be configured.

SCSICLUSTER_P[1-4]

(Alpha only) SCSICLUSTER_P[1-4] parameters allow non-Compaq peripherals (CPU-lookalikes) in SCSI clusters.

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

SCSMAXDG (G)

This parameter is reserved for Compaq use only.

SCSMAXMSG (G)

This parameter is reserved for Compaq use only.

SCSNODE (A,G)

SCSNODE specifies the name of the computer. This parameter is not dynamic.

Specify SCSNODE as a string of up to six characters. Enclose the string in quotation marks.

If the computer is in an OpenVMS Cluster, specify a value that is unique within the cluster. Do not specify the null string.

If the computer is running DECnet for OpenVMS, the value must be the same as the DECnet node name.

SCSRESPCNT (A,F,G)

SCSRESPCNT is the total number of response descriptor table entries (RDTEs) configured for use by all system applications.

If SCA or DSA ports are not configured on your system, the system ignores SCSRESPCNT.

SCSSYSTEMID (G)

Specifies a number that identifies the computer. This parameter is not dynamic. SCSSYSTEMID is the low-order 32 bits of the 48-bit system identification number.

If the computer is in an OpenVMS Cluster, specify a value that is unique within the cluster. Do not use zero as the value.

If the computer is running DECnet for OpenVMS, calculate the value from the DECnet address using the following formula:

SCSSYSTEMID = ((DECnet area number) * 1024) + (DECnet node number)

Example: If the DECnet address is 2.211, calculate the value as follows:

SCSSYSTEMID = (2 * 1024) + 211 = 2259

SCSSYSTEMIDH (G)

Specifies the high-order 16 bits of the 48-bit system identification number. This parameter must be set to 0. It is reserved by Compaq for future use.

SECURITY_POLICY

SECURITY_POLICY allows a system to run in a C2 or B1 configuration and subset out particular pieces of functionality that are outside of the evaluated configuration or to preserve compatibility with previous versions of the operating system. See the OpenVMS Guide to System Security for further information about the C2 and B1 evaluated configurations.

The following bits are defined:

Bit Description

0 Allows DECwindows to display PostScript extensions

1 Allows multiple user names to connect to DECW$SERVER

2 Allows unevaluated DECwindows transports (such as TCP/IP)

3 Allows $SIGPRC and $PRCTERM to span job trees

4 Allows security profile changes to protected objects on a local node when the object server is absent and cannot update the cluster database VMS$OBJECTS.DAT

5 Allows creation of protected objects on a local node when the object server is absent and cannot update the cluster database VMS$OBJECTS.DAT

6 Allows SPAWN or LIB$SPAWN commands in CAPTIVE accounts

Bit	Description
0	Allows DECwindows to display PostScript extensions
1	Allows multiple user names to connect to DECW$SERVER
2	Allows unevaluated DECwindows transports (such as TCP/IP)
3	Allows $SIGPRC and $PRCTERM to span job trees
4	Allows security profile changes to protected objects on a local node when the object server is absent and cannot update the cluster database VMS$OBJECTS.DAT
5	Allows creation of protected objects on a local node when the object server is absent and cannot update the cluster database VMS$OBJECTS.DAT
6	Allows SPAWN or LIB$SPAWN commands in CAPTIVE accounts

The default value of 7 preserves compatibility with existing DECwindows Motif behavior. A value of 0 disables all unevaluated configurations.

SERVED_IO

This parameter is reserved for future use by Compaq.

SETTIME

SETTIME enables (1) or disables (0) solicitation of the time of day each time the system is booted. This parameter should usually be off (0), so that the system sets the time of day at boot time to the value of the processor time-of-day register. You can reset the time after the system is up with the DCL command SET TIME (see the OpenVMS DCL Dictionary).

SHADOWING

SHADOWING enables or disables shadowing and specifies the mode of shadowing operations that you want to enable. SHADOWING is a value that specifies the type of disk class driver that is loaded on the system: DUDRIVER, DSDRIVER, or SHDRIVER. See Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing.

Specify one of the following values:

Value¹ Description

0 No shadowing is enabled; SHDRIVER is not loaded. This is the default value.

2 Phase II shadowing enabled. SHDRIVER is loaded. Phase II shadowing provides shadowing of all disks located on a standalone system or an OpenVMS Cluster system.

Value¹	Description
0	No shadowing is enabled; SHDRIVER is not loaded. This is the default value.
2	Phase II shadowing enabled. SHDRIVER is loaded. Phase II shadowing provides shadowing of all disks located on a standalone system or an OpenVMS Cluster system.

¹Note that a parameter value of 1 represents Phase I, which is no longer supported. Instead, use Phase II shadowing.

SHADOW_MAX_COPY (A,D)

Use this parameter for Phase II shadowing only. The value of SHADOW_MAX_COPY controls how many parallel copy threads are allowed on a given node.

Carefully consider the needs of each shadowed VAX node when you set this parameter. Too high a value for SHADOW_MAX_COPY can affect performance by allowing too many copy threads to operate in parallel. Too low a value unnecessarily restricts the number of threads your system can effectively handle.

See Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing.

SHADOW_MBR_TMO (D)

SHADOW_MBR_TMO controls the amount of time the system tries to fail over physical members of a shadow set before removing them from the set. The SHADOW_MBR_TMO parameter replaces the temporary VMSD3 parameter used in prior releases.

The SHADOW_MBR_TMO parameter is valid for use only with Phase II of Volume Shadowing for OpenVMS. You cannot set this parameter for use with Phase I, which is obsolete.

Use the SHADOW_MBR_TMO parameter (a word) to specify the number of seconds, in decimal from 1 to 65,535, during which recovery of a repairable shadow set is attempted. If you do not specify a value or if you specify 0, the default delay of 20 seconds is used.

Because SHADOW_MBR_TMO is a dynamic parameter, you should use the SYSGEN command WRITE CURRENT to permanently change its value.

SHADOW_REMOVE_1

(Alpha only) SHADOW_REMOVE_1 is reserved for Compaq use only.

SHADOW_REMOVE_2

(Alpha only) SHADOW_REMOVE_2 is reserved for Compaq use only.

SHADOW_SYS_DISK

A SHADOW_SYS_DISK parameter value of 1 enables shadowing of the system disk. A value of 0 disables shadowing of the system disk. The default value is 0.

Also specify a system disk shadow set virtual unit number with the SHADOW_SYS_UNIT system parameter, unless the desired system disk unit number is DSA0.

To enable minimerge on a system disk, add the value 4096 to your existing SHADOW_SYS_DISK value. For example, if you have SHADOW_SYS_DISK set to a value of 1, change it to 4097 to enable minimerge. Also, be sure to set the DUMPSTYLE parameter to dump off system disk, as described in the OpenVMS System Manager's Manual.

SHADOW_SYS_TMO

The SHADOW_SYS_TMO parameter has the following two distinct uses:

At system boot time, when this is the first node in the cluster to boot and to create this specific shadow set. If the proposed shadow set is not currently mounted in the cluster, use this parameter to extend the time a booting system waits for all former members of the shadowed system disk to become available.
Once the system successfully mounts the virtual unit and begins normal operations. In this usage, the SHADOW_SYS_TMO parameter controls the time the operating system waits for errant members of a system disk. (Use the SHADOW_MBR_TMO parameter to control the time the operating system waits for the errant members of an application disk.)

This parameter applies only to members of the system disk shadow set. All nodes using a particular system disk shadow set should have their SHADOW_SYS_TMO parameter set to the same value once normal operations begin.

The default value is 20 seconds. Change this parameter to a higher value if you want the system to wait more than the 20-second default for all members to join the shadow set. You can set the parameter value to 20 through 65,535 seconds.

SHADOW_SYS_UNIT

Use this parameter for Phase II shadowing only. The SHADOW_SYS_ UNIT parameter is an integer value that contains the virtual unit number of the system disk. The default value is 0. The maximum value allowed is 9999. This parameter is effective only when the SHADOW_SYS_DISK parameter has a value of 1. This parameter should be set to the same value on all nodes booting off a particular system disk shadow set. See Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing.

SHADOW_SYS_WAIT

The SHADOW_SYS_WAIT parameter extends the time a booting system waits for all current members of a mounted shadowed system disk to become available to this node. The shadow set must already be mounted by at least one other cluster node for this parameter to take effect.

The default value is 256 seconds. Change this parameter to a higher value if you want the system to wait more than the 256-second default for all members to join the shadow set. You can set the parameter value to 1 through 65,535 seconds.

SMCI_FLAGS (D)

(Alpha Galaxy platforms only) The SMCI_FLAGS parameter controls operational aspects of SYS$PBDRIVER, the Galaxy Shared Memory Cluster Interconnect (SMCI).

Bits in the bit mask are the following:

Bit Mask Description

0 0 0 = Do not create local communications channels (SYSGEN default). Local SCS communications are primarily used in test situations and are not needed for normal operations. Not creating local communications saves resources and overhead.

1 = Create local communications channels.

1 2 0 = Load SYS$PBDRIVER if booting into both a Galaxy and a Cluster (SYSGEN Default).

1 = Load SYS$PBDRIVER if booting into a Galaxy.

2 4 0 = Minimal console output (SYSGEN default).

1 = Full console output; SYS$PBDRIVER displays console messages when it creates and tears down communications channels.

Bit	Mask	Description
0	0	0 =	Do not create local communications channels (SYSGEN default). Local SCS communications are primarily used in test situations and are not needed for normal operations. Not creating local communications saves resources and overhead.
		1 =	Create local communications channels.
1	2	0 =	Load SYS$PBDRIVER if booting into both a Galaxy and a Cluster (SYSGEN Default).
		1 =	Load SYS$PBDRIVER if booting into a Galaxy.
2	4	0 =	Minimal console output (SYSGEN default).
		1 =	Full console output; SYS$PBDRIVER displays console messages when it creates and tears down communications channels.

SMCI_PORTS

(Alpha Galaxy platforms only) The Shared Memory Cluster Interconnect (SMCI) system parameter SMCI_PORTS controls initial loading of SYS$PBDRIVER. This parameter is a bit mask; bits 0 through 25 each represent a controller letter. If bit 0 is set, which is the default setting, PBAx is loaded (where x represents the Galaxy Partition ID). If bit 1 is set, PBBx is loaded, and so on up to bit 25, which causes PBZx to be loaded. For OpenVMS Alpha Version 7.2, Compaq recommends leaving this parameter at the default value of 1.

Loading additional ports allows multiple paths between Galaxy instances. In the initial release of the Galaxy software, having multiple communications channels is not an advantage because SYS$PBDRIVER does not support fast path. A future release of OpenVMS will provide Fast Path support for SYS$PBDRIVER, when multiple CPUs improve throughput by providing multiple communications channels between instances.

SMP_CPUS

SMP_CPUS identifies which secondary processors, if available, are to be booted into the multiprocessing system at boot time. SMP_CPUS is a 32-bit mask; if the value of a bit in the mask is 1, the processor with the corresponding CPU ID is booted into the multiprocessing system (if it is available). For example, if you want to boot only the CPUs with CPU IDs 0 and 1, specify the value 3 (both bits are on).

The default value of SMP_CPUS, --1, boots all available CPUs into the multiprocessing system.

Note that although a bit in the mask corresponds to the primary processor's CPU ID, the primary processor is always booted. That is, if the mask is set to 0, the primary CPU still boots. Any available secondary processors are not booted into the multiprocessing system.

This parameter is ignored if the MULTIPROCESSING parameter is set to 0.

SMP_CPUSH

SMP_CPUSH is a special parameter reserved for Compaq use only. Compaq recommends that you use the default value.

SMP_LNGSPINWAIT

Certain shared resources in a multiprocessing system take longer to become available than allowed by the SMP_SPINWAIT parameter. SMP_LNGSPINWAIT establishes, in 10-microsecond intervals, the length of time a processor in a multiprocessing system waits for these resources. A timeout causes a CPUSPINWAIT bugcheck.

The default value is 3 seconds (300,000 10-microsecond intervals).

SMP_SANITY_CNT

SMP_SANITY_CNT establishes, in 10-millisecond intervals, the timeout period for each CPU in a symmetric multiprocessing (SMP) system. Each CPU in an SMP system monitors the sanity timer of one other CPU in the configuration to detect hardware or software failures. If allowed to go undetected, these failures could cause the cluster to hang. A timeout causes a CPUSANITY bugcheck.

The default value is 300 milliseconds (30 10-millisecond intervals).

SMP_SPINWAIT

SMP_SPINWAIT establishes, in 10-microsecond intervals, the amount of time a CPU in an SMP system normally waits for access to a shared resource. This process is called spinwaiting.

A timeout causes a CPUSPINWAIT bugcheck.

The default value is 100 milliseconds (10,000 10-microsecond intervals).

SMP_TICK_CNT

SMP_TICK_CNT sets the frequency of sanity timer checks by each CPU in a multiprocessing system.

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

SPTREQ (A)

(VAX only) SPTREQ sets the number of system page table (SPT) entries required for mapping the following components:

Executive image
RMS image
SYSMSG.EXE file
Multiport memory structures
Each MASSBUS adapter
Each UNIBUS adapter
Each DR32 adapter

The number of system page table entries required for all other purposes is automatically computed and added to the value of SPTREQ to yield the actual size of the system page table.

SSINHIBIT

SSINHIBIT controls whether system services are inhibited (1) (on a per-process basis). By default, system services are not inhibited (0).

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

STARTUP_P1--8

STARTUP_P1 specifies the type of system boot the system-independent startup procedure is to perform. If STARTUP_P1 is " ", a full boot is performed; "MIN" indicates a minimum boot that starts only what is absolutely necessary for the operating system to run.

STARTUP_P2 controls whether verification is set during the execution of the system-independent startup procedure. If STARTUP_P2 is " ", verification is not enabled; "TRUE" indicates that verification is enabled.

Beginning in OpenVMS Version 7.2, if STARTUP_P3 is set to AGEN, the system executes AUTOGEN at the end of the startup sequence.

STARTUP_P4 through STARTUP_P8 are reserved for future use.

SWP_PRIO

SWP_PRIO sets the priority of I/O transfers initiated by the swapper.

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

SWPALLOCINC

(VAX only) SWPALLOCINC sets the size (in blocks) to use to back up swap file space allocation in the swap or page file. Space in the file is allocated in multiples of this unit (up to WSQUOTA) to guarantee swap space.

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

SWPFAIL

SWPFAIL sets the number of consecutive swap failures allowed before the swap schedule algorithm is changed to ignore the swap quantum protection.

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

SWPFILCNT

SWPFILCNT defines the maximum number of swap files that can be installed.

SWPOUTPGCNT (A on VAX,D)

This parameter allows the swapper an alternative mechanism before actually performing swaps.

On VAX systems, SWPOUTPGCNT defines the minimum number of pages to which the swapper should attempt to reduce a process before swapping it out. The pages taken from the process are placed into the free-page list.

On Alpha systems, SWPOUTPGCNT defines the minimum number of pagelets to which the swapper should attempt to reduce a process before swapping it out. The pagelets taken from the process are placed into the free-page list.

SWPRATE

SWPRATE sets the swapping rate (in 10-millisecond units). This parameter limits the amount of disk bandwidth consumed by swapping.

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

SYSMWCNT (A,G,M)

SYSMWCNT sets the quota for the size of the system working set, which contains the pageable portions of the system, the paged dynamic pool, RMS, and the resident portion of the system message file.

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