How to uncompress the AIX dump.BZ file?

 

From the: AIX 5L Differences Guide  Version 5.3 Addendum (SG24-7414-00)

 

3.6.7 The dmpuncompress command (5300-05)

 

A main change for AIX 5L Version 5.3 with TL 5300-05 of dump format is that the compressed dump will not use the compress command format, so it cannot be extracted by the uncompress command. A new dump compression method is introduced, and the copied dump has a name with suffix of .BZ instead of a .Z.

 

So, a new dmpuncompress command is added to extract the new-format compressed dump file.

 

The syntax is as follows:

 

The dmpuncompress command restores original dump files.  Each compressed file specified by the File parameter is removed and replaced by an expanded copy. The expanded file has the same name as the compressed version, but without the .BZextension. If the user has root authority, the expanded file retains the same owner, group, modes, and modification time as the original file. If the user does not have root authority, the file retains the same modes and modification time, but acquires a new owner and group.

 

The -f File flag forces expansion. It will overwrite the file if it already exists. The system does not prompt the user to know that an existing file will be overwritten. File size might not actually shrink in cases where data compression is already high.

 

The following is an example showing the dmpuncompress operation on the dump.BZ file:

-- replaced with vmcore

#

 

The dump.BZfile is uncompressed and renamed dump.