What is /dev/md2?

Question

Specifically, what might "A Fail event had been detected on md device /dev/md2." ramify?

(in an email from Plesk control panel's "Logwatch" BTW)

Solution 1

/dev/md* are raid devices. a fail event usually indicates that one of the hard drives on the raid array is dead/going to die. contact your hosting provider about this error, they may have to replace a defective disk.

Solution 2

As omry said, that's raid device. It can be mounted directly, or shielded by LVM.

In typical case you can work uninterrupted after getting the error mentioned, but your drive is not mirrored anymore.

Take a look at /proc/mdstat if you have access to this file, you may find more details there.