Extend the disk to increase its size or free up the space on the volume by deleting unwanted files or stale retention files. ...

Extend the disk to increase its size or free up the space on the volume by deleting unwanted files or stale retention files. (The retention drive is R: for Windows and /mnt/retention/ for Linux type Master Target servers). Else, re-protect physical or virtual machines with lower retention window or to a different Master Target server.