So there seems to be a change in the way raid-check works by default from RHEL 8 to RHEL 9 that is not documented anywhere. In RHEL 8 we seemingly used a cron job to run raid-check weekly if it was enabled:

RHEL 8:

ENABLED=yes
CHECK=check
NICE=low

1. To check devs /dev/md0 and /dev/md3, use "md0 md3"
   CHECK_DEVS=""
   REPAIR_DEVS=""
   SKIP_DEVS=""
   MAXCONCURRENT=

[root@dhcp-1-183-74 ~]# cat /etc/cron.d/raid-check

1. Run system wide raid-check once a week on Sunday at 1am by default
   0 1 * * Sun root /usr/sbin/raid-check

In RHEL 9 there is no cron job and instead it seems as though we moved this to be a systemd.timer and one shot service:

RHEL 9:

ENABLED=yes
CHECK=check
NICE=low

1. To check devs /dev/md0 and /dev/md3, use "md0 md3"
   CHECK_DEVS=""
   REPAIR_DEVS=""
   SKIP_DEVS=""
   MAXCONCURRENT=

[root@localhost ~]# cat /etc/cron.d/raid-check
cat: /etc/cron.d/raid-check: No such file or directory

[root@localhost system]# cat /usr/lib/systemd/system/raid-check.
raid-check.service raid-check.timer
[root@localhost system]# cat /usr/lib/systemd/system/raid-check.service
[Unit]
Description=RAID setup health check

[Service]
Type=oneshot
ExecStart=/usr/sbin/raid-check
[root@localhost system]# cat /usr/lib/systemd/system/raid-check.timer
[Unit]
Description=Weekly RAID setup health check

[Timer]
OnCalendar=Sun * 01:00:00
Persistent=true
AccuracySec=24h

[Install]

Additionally, it seems as though this timer is NOT enabled by default. So even if we enable the config for raid-check, we still have an additional step of enabling the raid-check.timer service in order for this service to show in the systemctl list-timers output and be scheduled.

I would like to know:
a) the expectation for this, i.e are we now expecting this to no longer be enabled by default by simply enabling the raid-check config as it worked in RHEL 8
b) if we can get some documentation for this change for how raid-check functions for RHEL 9+

I have attached the customer case to this Jira as well for tracking