Score:3

What is the source of syslog message "Condition check resulted in MD array scrubbing"

cn flag

On an Ubuntu 20.04.2 server with a software MD raid, exactly once a day when the system is doing its daily activities, the following message is output to the syslog:

systemd[1]: Condition check resulted in MD array scrubbing - continuation being skipped.

There are no issues with the MD raid. It is not in a degraded state and there have been no errors.

Although the message seems to imply that it is performing MD array scrubbing, that is certainly not the case. The array is large and scrubbing takes a long time and I have verified that the only time it is scrubbing is at the beginning of the month as triggered by mdadm.

I have not been able to find the source of that message or what it is trying to tell me. Could someone please point me in the right direction.

Michael Hampton avatar
cz flag
Search for the message in the journal to get more information: `journalctl -g "Condition check resulted in MD array scrubbing" -o verbose`
Score:4
ca flag

It simply means that the service responsible to continue a scrub was skipped because it was not necessary - ie: the condition to run it was not satisfied, for example because not much time passed since the last scrub.

More specifically, the unit mdcheck_continue.service check for the condition ConditionPathExistsGlob = /var/lib/mdcheck/MD_UUID_* meaning that it check for started-but-interrupted scrubs. You see the message each day because a timer called mdcheck_continue.timer is configured to start, each day, the mdcheck_continue.service unit.

So:

  • mdcheck_continue.timer elapses;
  • mdcheck_continue.service is invoked;
  • as no array should be scrubbed, mdcheck_continue.service logs and exits.
cn flag
It was the wording of the message that was throwing me. Now that I have read your answer and looked at the scripts involved, I see that. The log message should really read: Condition check resulted in _"MD array scrubbing - continuation"_ being skipped. Thanks!
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