Today (in 2020, with init systemd), there seem to be many ways to schedule tasks (something I assume previously made by the crond daemon).
My trouble is to understand why there are three packages somewhat named similarly cronie..... available on my RHEL7 setup. This question seeks to get at the bottom about what makes those packages different in their use case.
When for instance would one prefere any of cronie/cronie-anacron/cronie-noanacron package. Are those packages interdependent?
The information provided via YUM is this:
[root@localhost ~]# yum search cronie
Loaded plugins: product-id, search-disabled-repos, subscription-manager
This system is not registered with an entitlement server. You can use subscription-manager to register.
============================= N/S matched: cronie ==============================
cronie.x86_64 : Cron daemon for executing programs at set times
cronie-anacron.x86_64 : Utility for running regular jobs
cronie-noanacron.x86_64 : Utility for running simple regular jobs in old cron style
I have read this resource that comparese cron with anacron basically saying that anacron's use case is to schedule stuff that has to occur at intervals of days and on systems not running 24/7.
What is most puzzling is then the cronie-noanacron thing.
** Update **
Looking into the matter I have stumpled upon this quote:
Now I get it. Cronie package by itself does not execute cron.daily, weekly&monthly scripts.../etc/crontab is empty. Scripts are executed either by anacron or /etc/cron.d/dailyjobs (cronie-noanacron) so cronie package depends on either cronie-anacron or cronie-noanacron to actually function as crond did. Installing cronie-noanacron will enable uninstalling cronie-anacron without breaking dependencies.
from https://forums.centos.org/viewtopic.php?f=13&t=1040&start=10#p6438
Can somebody confirm this? (since this would kind of give some insight/ answer to the question)