How to test a hard drive in Ubuntu on a production web server?

Question

Hard disks

Hello.
There is a hard drive on the production server (RAID), how to check it for error-free? At the same time, it is spinning on a production web server.
How, in general, to correctly diagnose the production server, so that nothing stops and works as it should?
There is, of course, an option, to reconfigure everything from it to another server, and calmly check it out of service, but still.

Answer 1

In fact, RAID assumes the presence of more than one hard drive ...
In general, if the RAID is in order, then the disks are too.
And the ability to view SMART and somehow diagnose individual disks depends on the implementation of RAID.

Answer 2

in any case, it is necessary to transfer the services to another server, carry out diagnostics, and then decide whether it is worth transferring back.