Tippett uses Silicon Graphics Irix servers. With the Irix systems, system administration chores can be conducted while the servers continue to process graphics files. Yesterday I saw an NT system put up an irreparable 'Blue Screen of Death' upon boot up simply because someone took a sound card out of the machine. The machine refused to boot until the sound card was reinstalled. If a trivial peripheral like a sound card dies, it can keep an NT system from booting.
Some operating systems support live installation or live swapping of hardware and software drivers.
This allows changes in system configuration while the system remains running. This means you can boot Linux and reconfigure its support for hardware and software on the fly. For example, you can boot Linux without support for the SCSI card you have installed. You simply load support for that SCSI card when you need to access one or more of the SCSI-connected devices, such as an optical disk for backup. You can unload the SCSI driver when you're finished.