Add crontab entry to create edge reference storage partitions
This implements the last entry of swh/infra/sysadm-environment#4911 (closed)
(the first commit fixes a shortcoming of the detection of journal writers)
Staging instance, all changes can be removed at any time
This implements the last entry of swh/infra/sysadm-environment#4911 (closed)
(the first commit fixes a shortcoming of the detection of journal writers)