Tip: my notes on 28's new core dump

[ToddAndMargo]

Hi All,

    Fedora changed the way core dumps are generated.
These are my notes:

-T


Fedora 28+ core dumps:

As of Fedora 28, core dumps have to be extracted by the administrator 
(root):

These commands will give you a list of core dumps

         # coredumpctl --reverse list
         # ls -l /var/lib/systemd/coredump/

You need the PID of the core dumps parent to create a coe dump:

     coredumpctl has a PID column.  "--reverse" puts the youngest at the 
top:

     # coredumpctl --reverse list
     TIME                            PID   UID   GID SIG COREFILE  EXE
     Wed 2018-02-21 12:00:46 PST   20759     0     0   6 missing 
/opt/Cimcor/CimTrak/CimT


     # ls -l /var/lib/systemd/coredump/
     -rw-r-----. 1 root root 1622777 May 31 03:04 
core.CimTrakServer\x2eb.0.a91f9e4dc86f4e7ea65bd7dbd7eb5429.28086.1527761078000000.lz4

     The second to last set of numbers (28086 above) is the PID


To find a particular program's youngest pid (sub program name for 
"CimTrak"):
     # coredumpctl --reverse list | perl6 -e 'my $x=slurp(); for split 
"\n", $x -> $Line {if $Line ~~ / CimTrak / { say $Line.words[4]; last }
};'
     9405



To extract a core dump:

    # coredumpctl dump {PID} --output /tmp/{PID}.core
    This will place the Core file will be located in /tmp/

    For example:
         # coredumpctl dump 9405 --output /tmp/9405.core