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This section contains the following topics: System Hardware Requirements on OpenVMS SYSGEN Parameters that Affect Operation |
Note: The recommended values mentioned in this appendix are for a minimal Ingres installation. Requirements for your system may vary, depending on the products you install and the maximum number of users. For values that may be better suited to your environment, see the Ingres technical support page, accessible from http://ingres.com.
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The following table describes typical system hardware requirements.
Note: Check the Readme file for changes to the following requirements that are specific to your platform.
Element |
Typical Requirement |
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Number of disks |
At least two separate storage devices for your databases and checkpoint files are strongly recommended. |
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Disk space |
The amount of space required on any one particular disk is determined by the number of disks in your configuration, the packages you are installing, and the locations you choose for your files. Peak system disk utilization is approximately 1.2 x kit size. The default file size for your primary and backup transaction log files is 32 MB. However, the recommended size is between 100 and 400 MB, or larger. For help in determining space requirements for II_DATABASE, see the Database Administrator Guide. |
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Physical Memory |
For a DBMS Server installation: |
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OS |
Required |
Recommended |
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Alpha |
128 MB |
512 MB or more |
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It is important to understand the way OpenVMS parameter settings affect Ingres.
For information on tuning OpenVMS, see your OpenVMS documentation.
Note: Check the Readme file for changes to the following requirements that are specific to your platform.
The following table lists SYSGEN parameters that affect Ingres operation:
Element |
Description |
Considerations |
|---|---|---|
CHANNELCNT |
Number of open I/O channels permitted each OpenVMS process at any one time |
This parameter is critical to the successful execution of the DBMS Server. If the setting is too large, it wastes system memory; if too small, it limits Ingres I/O capabilities. Since the DBMS is multi-threaded, it effectively requires the same CHANNELCNT setting as if it were several individual processes. |
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Use the following formula to calculate an approximate value, where sessions is the total number of connected sessions and file_limit is the total number of files that can be open at one time: CHANNELCNT = (sessions * 4) + file_limit In general, set CHANNELCNT to a very large number. The file_limit (fillm) requirements will vary over time. The DBMS Server will, at most, open every file in every database, plus approximately five for the transaction log and error log files. |
GBLSECTIONS |
Determines the maximum number of global sections that can be made known to the system by allocating the necessary storage for the Global Storage Table (GST) entries Example value for Alpha: 800 |
Several Ingres components use global pages of memory to enable multiple processes to share data. Examples are:
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GBLPAGES |
Determines the size of the global page table and the limit for the total number of global pages that can be created Example value for Alpha: 250,000 |
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GBLPAGFIL |
Establishes the maximum number of global pages with page file "Backing Storage Address" storage that can be created Example Value for Alpha: 40,000 |
On Alpha, memory pages are at least 8 KB in size. At this size, four Ingres pages fit in each Alpha memory page. Note that Alpha pages can be from 8 KB to 16 KB in size. See your OpenVMS Alpha documentation. To examine entries and available pages and sections, use the INSTALL utility and issue LIST/GLOBAL and LIST/GLOBAL/SUMMARY. |
NPAGEDYN |
Non-paged dynamic pool; determines the number of bytes to allocate for the non-pages dynamic pool |
Used in allocating the logging and locking system in previous Ingres releases. Ingres uses GBLPAGES (global pages) rather than NPAGEDYN and NPAGEVIR to allocate the logging and locking system shared memory at startup time. |
NPAGEVIR |
Virtual non-paged pool; determines the number of bytes to which the non-paged pool may be extended |
Used in allocating the logging and locking system in previous Ingres releases. Ingres uses GBLPAGES (global pages) rather than NPAGEDYN and NPAGEVIR to allocate the logging and locking system shared memory at startup time. |
PQL_* |
PQL_parameters; PQL_D is the default and PQL_M is the minimum process quotas that OpenVMS uses when creating detached processes (of which Ingres generates several) |
If a value is not specified on the command line when Ingres processes are started, the PQL default is used. If the process specifies a value below the PQL minimum, the current minimum is used. If the creator has DETACH privilege, any of the values can be overridden, which is crucial to the successful startup of Ingres processes. To examine the resulting process configuration, use: SHOW PROCESS/QUOTA/ID=pid |
VIRTUALPAGECNT |
Maximum virtual page count; determines the total number of pages that can be mapped for a process, which can be divided in any fashion between P0 and P1 space Beginning with OpenVMS 7.0, this parameter ceased to be tunable on Alpha as the process page tables have migrated from system space to a dedicated page table space. See your OpenVMS documentation for details. |
The DBMS Server process can grow to require large numbers of virtual pages due to the complexity of its facilities and their various caches. It is critical that this process be able to expand its memory regions as necessary. If an error occurs while trying to expand the virtual size of the server, first examine the process page file quota, and then examine this system-wide limit. To do so, set the process page file quota to the current VIRTUALPAGECNT and start the server. If this does not resolve the problem, this parameter needs to be adjusted upwards. To examine current usage, use: SHOW PROCESS/QUOTA/ID=pid |
WSMAX |
Maximum size of process working set; determines the system-wide maximum size of a process working set, regardless of process quota Example value for Alpha: 130,000 |
This parameter limits the size of the physical memory that any OpenVMS process can grow to consume. To prevent Ingres processes from spending overhead page faulting, be sure to configure them with a working set large enough to reduce or eliminate the amount of swapping and/or paging required. Distinguish hard faults (disk reads/writes, which are expensive) from soft faults (memory read/writes, which are more tolerable). |
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Check and set the OpenVMS process resources, if necessary, for the following accounts:
Almost all OpenVMS process quotas impart a cost only when a given resource is requested and consumed. If you limit the Ingres process resources, it may function, but its performance may be impaired. Therefore, we generally recommend high resource quotas for the system administrator account. If performance is a critical issue, try setting the quota to infinity, if permitted.
The following table shows the recommended minimum process resources for the system administrator. When the install program creates the system administrator account, it automatically sets the process resources to the recommended minimums shown in the table.
Database administrators who checkpoint their own databases (as opposed to the system administrator) indirectly use OpenVMS backup. You should set UAF parameters for their accounts. For details, see the OpenVMS backup manual.
UAF Name |
Description |
Recommended Starting Value |
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BYTLM |
Buffered I/O byte count limit |
500,000 |
TQELM |
Timer queue entry limit |
40 |
PGFLQUO |
Paging file quota (possibly set to the system virtual page count) |
250,000 |
DIOLM |
Direct I/O count limit |
200 |
BIOLM |
Buffered I/O limit |
400 |
FILLM |
Open file limit |
1000 |
PRCLM |
Subprocess creation limit |
15 or larger - Alpha |
ASTLM |
AST queue limit |
200 |
ENQLM |
Enqueue limit (non-cluster) |
2048 |
JTQUOTA |
Job logical name table byte limit |
20,000 |
MAXDETACH |
Maximum detached processes limit |
0 (infinity) |
PRIV |
Privileges |
ALTPRI, CMKRNL, IMPERSONATE, EXQUOTA, OPER, PRMGBL, PRMMBX, READALL, SHARE, SYSGBL, SYSLCK, SYSNAM, SYSPRV, TMPMBX, WORLD |
DEVICE |
Device and directory for default login |
II_SYSTEM:[Ingres ] |
DEFPRIV |
Default privileges |
ALTPRI, CMKRNL, IMPERSONATE, EXQUOTA, OPER, PRMGBL, PRMMBX, READALL, SHARE, SYSGBL, SYSLCK, SYSNAM, SYSPRV, TMPMBX, WORLD |
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OpenVMS quotas and their corresponding Ingres parameters are listed here. Adjust the Ingres parameters using Configuration-By-Forms to reflect the OpenVMS quota settings.
Ingres Configuration |
OpenVMS (Authorize) Entry |
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vms_ast_limit |
ASTlm |
vms_buffer_limit |
BYTlm |
vms_extent |
Wsextent |
vms_file_limit |
Fillm |
vms_io_buffered |
BIOlm |
vms_io_direct |
DIOlm |
vms_maximum_working_set |
Wsquo |
vms_page_file |
Pgflquo |
vms_privileges |
DEFPRIVILEGES |
vms_queue_limit |
Enqlm |
vms_working_set |
Wsdef |
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The system administrator account must have the following OpenVMS privileges:
ALTPRI
CMKRNL
EXQUOTA
IMPERSONATE
OPER
NETMBX
PRMGBL
PRMMBX
READALL
SHARE
SYSGBL
SYSLCK
SYSNAM
SYSPRV
TMPMBX
WORLD
If the install program creates the system administrator account, it automatically assigns these privileges.
Note: If you want to turn off the vms_accounting parameters, which allow the Ingres processes to be started without a record in the VMS accounting file, the system administrator will also need the ACNT privilege. (If this is the case, all processes started by the administrator will not be in the VMS accounting audit trail).