HP OpenVMS Systems Documentation
OpenVMS System Manager's Manual
16.12 Copying System Dump Files to Tape or Disk
If your system fails, make a copy of the contents of the system dump file and contact your Compaq support representative. You can use the Backup utility (BACKUP) to create save sets containing system dump files on magnetic tape or disk. However, when using BACKUP to copy system dump files, you must specify the /IGNORE=(NOBACKUP,INTERLOCK) qualifier for the following reasons:
Compaq recommends that you use the following procedure to copy your system dump file:
This procedure avoids issues with BACKUP qualifiers and reduces the
amount of data written to tape or disk because the SDA command COPY
copies only blocks in the system dump file that are actually used.
If you use SYS$SYSTEM:PAGEFILE.SYS to store a system crash dump, you must later free the space occupied by the system dump for use by the pager. If you do not, your system might hang because of insufficient paging space.
Section 16.1.1 explains when you might use the page file to store a
system crash dump.
This section contains instructions for freeing dump information from the page file on VAX and Alpha systems.
On VAX systems, perform the following steps:
Alternatively, to free the pages in the page file that are taken up by the dump without having to copy the dump elsewhere, enter the ANALYZE/CRASH_DUMP/RELEASE command. This command immediately releases the pages to be used for system paging, effectively deleting the dump. Note that this command does not allow you to analyze the dump before deleting it.
The following commands, added to the SYSTARTUP_VMS.COM command procedure, copy the contents of the page file to a file named SAVEDUMP.DMP:
On Alpha systems, as described in the OpenVMS Alpha System Analysis Tools Manual, SDA is automatically invoked by default when the system is rebooted after a system failure.
To automatically save the system dump file, perform the following steps:
If the logical CLUE$INHIBIT has been defined, and SDA has not been automatically invoked during system startup, the pages in the page file that are taken up by the dump can be released using the ANALYZE/CRASH_DUMP/RELEASE command. This command immediately releases the pages to be used for system paging, effectively deleting the dump. Note that this command does not allow you to analyze the dump before deleting it.
For a discussion of logical names used by CLUE, refer to OpenVMS Alpha System Analysis Tools Manual.
Because a system dump file can contain privileged information, protect copies of dump files from world read access.
Although you can also use the DCL command COPY to copy a dump file, Compaq recommends that you use the SDA command COPY because SDA COPY performs the following actions:
16.14 Installing Page and Swap Files
The system automatically installs the primary page and swap files
located in SYS$SYSTEM. However, other page and swap files are not
automatically installed. For this reason, if you create secondary page
and swap files, you must also install them with the System Generation
utility (SYSGEN). Note that SYSGEN INSTALL commands perform a different
function than Install utility (INSTALL) commands.
The following example installs page and swap files interactively:
16.14.2 Installing in SYPAGSWPFILES.COM
Page and swap files other than SYS$SYSTEM:PAGEFILE.SYS and SYS$SYSTEM:SWAPFILE.SYS must be reinstalled each time the system boots. You can do this by adding the commands to install the files to the startup command procedure SYS$MANAGER:SYPAGSWPFILES.COM. The template file SYS$MANAGER:SYPAGSWPFILES.TEMPLATE includes comments that help explain how this file is used.
Before performing this task, you must have created the secondary files, as explained in Section 16.16.
For more information about SYPAGSWPFILES.COM, see Section 5.2.3.
You can also use SATELLITE_PAGE.COM to install page and swap files on an OpenVMS Cluster satellite node's local disk. SATELLITE_PAGE.COM is created when you run CLUSTER_CONFIG.COM. For more information about installing page and swap files on a satellite node's local disk, refer to the OpenVMS Cluster Systems manual.
The following example shows commands you might add to SYPAGSWPFILES.COM to install page and swap files named PAGEFILE_1.SYS and SWAPFILE_1.SYS located on the DUA2: device:
16.15 Removing Page, Swap, and Dump Files
16.16 Creating and Modifying Page, Swap, and Dump Files
For performance or disk space reasons, you might want to create system page, swap, and dump files on disks other than the system disk. (Error log dump files, however, must remain on the system disk.)
The following sections explain how to perform this task:
16.16.1 Using AUTOGEN (Recommended Method)
You can direct AUTOGEN to create new system page, swap, and dump files by adding symbols to MODPARAMS.DAT to specify the name, location, and size of new files to be created and then running AUTOGEN. Before performing this task, you should understand AUTOGEN and its parameter file MODPARAMS.DAT. For more information about when to use AUTOGEN, see Section 15.4. See Section 15.4.4 for information about MODPARAMS.DAT.
AUTOGEN automatically calculates appropriate sizes for system page, swap, and dump files. It also modifies the files to the appropriate sizes and installs them. You can control sizes calculated by AUTOGEN by defining symbols in the file MODPARAMS.DAT. For more information, see Section 220.127.116.11.
18.104.22.168 Controlling the Location of System Page, Swap, and Dump Files
22.214.171.124 Controlling the Size of System Page, Swap, and Dump Files in MODPARAMS.DAT
You can add information to the AUTOGEN parameter file MODPARAMS.DAT to control the sizes that AUTOGEN calculates for system page, swap, and dump files. If you do not supply system file size information in MODPARAMS.DAT, AUTOGEN performs default size calculations for page, swap, and dump files.
You can define symbols in MODPARAMS.DAT to specify either of the following items:
For page and swap files, AUTOGEN generally manipulates the primary files SYS$SYSTEM:PAGEFILE.SYS and SYS$SYSTEM:SWAPFILE.SYS only if you have no other page and swap files. If you have secondary files, AUTOGEN manipulates the secondary files and excludes primary files. However, in some instances, AUTOGEN might modify the size of the primary page and swap files.
On VAX systems, for system dump files, AUTOGEN manipulates the size of only one file: the system dump file on the system disk if no DUMPFILE_DEVICE is given, or the system dump file on the specified device if DUMPFILE_DEVICE is specified.
On VAX systems, AUTOGEN always creates a minimal SYSDUMP.DMP file on the system disk for error log buffers if DUMPFILE_DEVICE is specified.
If you do not want AUTOGEN to change the sizes of the primary files, specify the following symbols in MODPARAMS.DAT:
These symbols direct AUTOGEN to ignore the primary page, swap, and dump files when calculating sizes.
If the creation or extension of a system page, swap, or dump file would cause the target disk to become more than 95 percent full, AUTOGEN issues a warning and does not perform the operation.
On Alpha systems, however, the 95 percent rule does not apply to the error log dump file, SYS$ERRLOG.DMP. This file is created if the disk can hold it.
You can use AUTOGEN to create a page, swap, or dump file that is smaller than the current version of the file. After you have booted and begun using the new file, remember to use the DCL command PURGE to reclaim the disk space from the old version of the file.
To determine the current sizes of installed page and swap files, enter the DCL command SHOW MEMORY/FILES. If you increased the size of any of these files and have not rebooted, this command displays the original sizes. Use the DIRECTORY command to determine the size of dump files.
Table 16-4 lists the symbols you can define in MODPARAMS.DAT to control the total size of page file, swap file, system dump file, or error log dump file space space.
1n is the total size, in blocks. If n is 0, the corresponding AUTOGEN section is skipped. For page and swap files, if n is not 0 and no secondary files exist, AUTOGEN applies the value to primary files. If n is not 0, and secondary files exist, AUTOGEN applies any change evenly across all secondary page or swap files but, in most cases, does not change primary files. For dump files, if n is not 0, AUTOGEN applies the value to the dump file on the system disk if no DUMPFILE_DEVICE is given or the dump file on the specified device if a DUMPFILE_DEVICE is given.
Table 16-5 lists the symbols you can define in MODPARAMS.DAT to control the size of individual files.
1For n, specify an integer that indicates the page or swap file. Refer to the primary page and swap files by specifying a value of 1 for n; refer to subsequent files by specifying increasingly higher integer values for n. For example, to refer to a secondary page or swap file, specify a value of 2 for n. For block-size, specify the size in blocks.