Solaris 11.4 SRU42 (Feb 2022) - /var/share/cores FS and coreadm defaults

/var/share/cores is now a separate filesystem

-bash-5.1$ zfs list rpool/VARSHARE/cores
NAME                  USED  AVAIL  REFER  MOUNTPOINT
rpool/VARSHARE/cores   31K  22.1G    31K  /var/share/cores

If you upgrade from a previous SRU to SRU42 or later,
cleanup /var/share/cores first, because the files
will be migrated to the new filesystem.


coreadm has now better defaults for the core file naming

root@marcel49:~# coreadm | head -3
     global core file pattern: /var/cores/core.%z.%f.%u.%p
     global core file content: default
kernel zone core file pattern: /var/cores/kzone.%z.%t

with this new core file pattern, the cores can be easier identified
and are less often overwritten.

root@marcel49:~# ls -lh /var/cores/core.marcel49.sleep.0.21198
-rw-------   1 root     root       4.16M Feb 25 13:19 /var/cores/core.marcel49.sleep.0.21198

If the pattern was not configured before the upgrade to SRU42 or later
the new default is set automatically.

If you used another pattern before you upgraded to SRU42 or later
you can set it manually to the new standard/default.

coreadm -g /var/cores/core.%z.%f.%u.%p