expand_dump(8)expand_dump(8)NAMEexpand_dump - Produces a non-compressed kernel crash dump file
/usr/sbin/expand_dump input-file output-file
By default, kernel crash dump files (vmzcore.#) are compressed during
the crash dump. Compressed core files can be examined by the latest
versions of debugging tools that have been recompiled to support com‐
pressed crash dump files. However, not all debugging tools may be
upgraded on a given system, or you may want to examine a crash dump
from a remote system using an older version of a tool. The expand_dump
utility produces a file that can be read by tools that have not been
upgraded to support compressed crash dump files. This non-compressed
version can also be read by any upgraded tool.
This utility can only be used with compressed crash dump files, and
does not support any other form of compressed file. You cannot use
other decompression tools such as compress, gzip, or zip on a com‐
pressed crash dump file.
Note that the non-compressed file will require significantly more disk
storage space as it is possible to achieve compression ratios of up to
60:1. Check the available disk space before running expand_dump and
estimate the size of the non-compressed file as follows: Run tests by
halting your system and forcing a crash as described in the Kernel
Debugging manual. Use an upgraded debugger to determine the value of
the variable dumpsize. Multiply this vale by the 8Kb page size to
approximate the required disk space of the non-compressed crash-dump.
Run expand_dump and pipe the output file to /dev/null, noting the size
of the file that is printed when expand_dump completes its task.
Successful completion of the decompression. The user did not supply
the correct number of command line arguments. The input file could not
be read. The input file is not a compressed dump, or is corrupted.
The output file could not be created or opened for writing and trun‐
cated. There was some problem writing to the output file (probably a
full disk). The input file is not formated consistantly. It is proba‐
bly corrupted. The input file could not be correctly decompressed. It
is probably corrupted.
EXAMPLESexpand_dump vmzcore.4 vmcore.4
Commands: dbx(1), kdbx(8), ladebug(1), savecore(8)