expand_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 compressed 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
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 compressed crash
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 esti-
mate 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 dump-
size. 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.
0 Successful completion of the decompression.
1 The user did not supply the correct number of command line arguments.
2 The input file could not be read.
3 The input file is not a compressed dump, or is corrupted.
4 The output file could not be created or opened for writing and trun-
5 There was some problem writing to the output file (probably a full
7 The input file is not formated consistantly. It is probably corrupted.
8 The input file could not be correctly decompressed. It is probably
expand_dump vmzcore.4 vmcore.4
Commands: dbx(1), kdbx(8), ladebug(1), savecore(8)