It would be possible to replace the defective hard drive hot-plug-in. But then it can happen that the new inserted hard disk gets a new identification (in our example /dev/sdb
can become /dev/sdc
). Therefore a restart of the server is recommended.
On some machines it can happen, that the boot order after a restart changes. In such a case just manually choose the boot drive. You can usually do this by pressing the 'ESC' or 'F8' key just after switching your computer on (check your computer manual).