/sys$common/syshlp/helplib.hlb SET, PROCESS, Qualifiers, /DUMP  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /DUMP[=NOW] [/ID=pid] [process-name]
       /NODUMP (default)

    Causes the contents of the address space to be written to the
    file named SYS$LOGIN:(image-name).DMP (where the image name is
    the same as the file name) when an image terminates due to an
    unhandled error. To specify a target process, indicate either the
    process ID or the process name.

    Using the NOW option causes the targeted process to dump as soon
    as possible. This is especially useful for hung processes.

    You can then analyze the dump with the ANALYZE/PROCESS_DUMP
    utility, the Debugger, or the System Dump Analyzer (SDA).