Step 1: Login to your IPMI interface by using https://[ip-address] in any browser.
Step 2: After you log in, Go to System > System Information Console Redirection, and then click Launch Console. This will launch a Java Console interface.
Step 3: After a few seconds a toolbar should load in this Java window. Click on Power Control, and choose Power Reset.[Note : Continuously press on F12]
Step 4: Now choose the preferred Os. Your OS reload has been initialized.
Here I am choosing Centos 7.
Click on Continue:
Step 5: Complete the Installation Destination.
Step 6: Here, you have to choose both options, and hit on "Done" button. Now, a new window opens > their select option "delete all". Once it's "delete"; you can adjust the partition by "Reclaim Space".
Step 7: Click on "Begin Installation"; and set a new root password.
Step 8: Now, if the installation is successful and reboot is complete; login page is loaded.