1. hardware, storage Writing duplicate data to more than one
device (usually two
hard disks), in order to protect against
loss of data in the event of device failure. This technique
may be implemented in either hardware (sharing a
diskcontroller and cables) or in software. It is a common
Interestingly, when this technique is used with
magnetictape storage systems, it is usually called "twinning".
A less expensive alternative, which only limits the amount of
data loss, is to make regular
backups from a single disk to
copy of some or all files at another site so as to make them
more quickly available to local users and to reduce the load
on the source site. Such mirroring is usually done for
specific whole directories or files on a specific remote
copies of everything that is requested via it.
For example, src.doc.ic.ac.uk is the main UK mirror for the
GNU archive at gnu.org. There are also several
(1998-06-11)