HP PL Class 450/500/550/600/650/700/750 Supplementary Manual page 18

System Recovery
This chapter describes two methods for recovering from damage to your
system hardware or software. The Linux Rescue Mode may allow you to
recover important files or solve the problem when you are unable to boot
the operating system. The Disaster Recovery procedure will reinstall the
original software that was installed on your workstation at the factory.
12 Chapter 2