Does mdadm record array event history?

Question

I received an automated email from the mdadm daemon:

A Fail event had been detected on md device /dev/md0.

It could be related to component device /dev/sdh.

I find the wording strange. "could be"? Was it sdh or not?

Does mdadm keep a history of such events with more detail?

I had a spare HDD in the array, so I guess it rebuilt itself, consuming the spare. There is now no mention of /dev/sdh from:

mdadm -D /dev/md0

How can I tell if there really was a failed HDD event, and the identity of that failed drive?

Kind regards,

John.

Solution

mdadm does not, itself, keep a history of its activity, however it should log what it is happening - depending on your distro, check /var/log/syslog /var/log/messages /var/log/debug /var/log/kernel.log - one of those files should contain the information you are after.