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 VSI use only.
Bit Mask Description
0 00000001 0 = Full dump. 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 VSI
OpenVMS System Manager's Manual
for details.)
3 00000008 0 = Do not compress.
1 = Compress.
4 00000010 0 = Dump shared memory (Alpha Galaxy
systems only).
1 = Do not dump shared memory.
5 00000020 0 = Dump all processes and global pages
in a selective or interleaved dump.
1 = Only dump key processes and global
pages
6 00000040 0 = Dump S2 space in a selective dump.
1 = Do not dump S2 space.
7 00000080 0 = Write a full or selective dump
based on the setting of bit 0.
1 = Write an interleaved dump
(x86-64 systems only).
8 - 31 Reserved for VSI use only.
For Alpha systems and Integrity servers, bit 7 is ignored.
For x86-64 systems, bits 2, 4, and 6 are ignored. (Instead of
setting bit 2 to specify an alternate dump device, use the
SET DUMP/DEVICE command). In addition, the following
combinations of bits are not supported:
- Neither bit 0 nor bit 7 is set (full dumps are not supported).
A selective dump will be written.
- Both bit 0 and bit 7 are set (a dump cannot be both selective
and interleaved). An interleaved dump will be written.
- Both bit 3 and bit 7 are set (interleaved dumps are always
compressed). Bit 3 will be ignored.
If you plan to enable the Volume Shadowing minimerge feature, be
sure to specify DOSD to an alternate disk.
NOTE
You can save space on the system disk and, in the event of
a crash, save time recording the system memory, by using
the dump compression feature. Unless you override the
default AUTOGEN calculations (by setting DUMPSTYLE in
MODPARAMS.DAT), AUTOGEN uses the following algorithm:
o 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.
o 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).
The mask of 00000009 directs the system to compress a selective
dump with minimal console output.
DUMPSTYLE has AUTOGEN and DYNAMIC attributes.