System information

Glossary-6 Endurance FTvirtual Server Administrator’s Guide
Unknown. The Endurance software cannot
determine the state of the component. This can be
caused by the loss of communication when a
remote CoServer is shut down.
UPS. Uninterruptable Power Supply. A battery-
operated device that provides a limited supply of
electrical power in the event of a power failure.
valid disk. A disk in a mirror set whose contents
are correct and up to date. Typically, a mirror set
has two valid disks. It is also possible for there to
be no valid disks in a mirror set. The source disk
for a mirror copy is a valid disk.
Virtual disk.
A virtual disk is a file that
exists on a CoServer disk and appears to the
CoServer as a separate disk. Virtual disks can
be mounted like a physical disk, managed
using the Windows Disk Management utility,
partitioned, and redirected to the FTvirtual
Server using the Device Redirector.
virtual network. LAN-style connectivity
between the FTvirtual Server and each CoServer.
This connectivity is independent of any public
(redirected) or private (CoServer) network
adapters.
Virtual Server. The Windows operating system
environments, one on each CoServer. When the
Virtual Servers are synchronized, with
redundancy, the operating system and applications
are fault tolerant.