Linux: How To Extend a ROOT(/) Filesystem that is on a Logical Volume Manager (LVM) Volume
This article describes how to extend the root filesystem "/" on Oracle Linux when it is located on an LVM volume. This procedure may be necessary if the root filesystem is too small and more space is needed for the system to perform basic administration tasks. It may also be needed if separate filesystems aren't used for /home or /var, as these directories can rapidly fill depending on how the server is being used.
NOTE: Take a backup of the server before attempting this procedure, as any mistakes could result in data loss, or impact on the functionality of the server. This procedure will need to be done in a maintenance window, as the root partition can't be extended while online and it will thus result in downtime for the server. This procedure should first be attempted on a test or non-production instance, so anyone attempting this procedure has tested these steps before trying them on a production instance.