Dump extractor (jextract)

(AIX®, Linux™, Start of content that applies only to Java 11 (LTS) and later macOS®End of content that applies only to Java 10 and later)

On some operating systems, copies of executable files and libraries are required for a full analysis of a core dump (you can get some information from the dump without these files, but not as much). Run the jextract utility to collect these extra files and package them into an archive file along with the core dump. To analyze the output, use the dump viewer (jdmpview).


    jextract <core file name> [<zip_file>]


  • <core file name> is the name of the system dump.
  • <zip_file> is the name you want to give to the processed file. If you do not specify a name, output is written to <core file name>.zip by default. The output is written to the same directory as the core file.
If you are analyzing a dump from a VM that used -Xcompressedrefs, include the -J-Xcompressedrefs parameter to run jextract using compressed references.

Restriction: You must run jextract using the same VM level, on the same system that produced the system dump. If you run jextract on a VM level that is different from the one on which the dump was produced you see the following messages:

J9RAS.buildID is incorrect (found e8801ed67d21c6be, expecting eb4173107d21c673).
This version of jextract is incompatible with this dump.
Failure detected during jextract, see previous message(s).

See also