Users who store data, programs etc. on any sort of
computer system are urged to give thought to the
provision of backup copies. It still happens that people
lose an entire program or thesis or book or important
data because, for instance, they have relied on a single
copy on a hard disk which ceases to work. You should
always aim to keep a second copy of work in progress
(not on the same disk), not out of date by more than a
few hours' worth of work. In case of disaster, a
reasonably up-to-date paper copy is better than nothing;
it may be possible, though laborious, to reconstruct the
document by scanning.
Backup is the end-user's responsibility; ITCC have some
central provision for backup storage space, user should
request, but you need to judge whether this is adequate
for your needs. If you are storing material on your own
equipment then backup is entirely your responsibility.
You may have valuable data, email or programs on a
system of your own on your desk, or it may be stored on
a system belonging to the Computing Service or a College
or Departmental network.
Computing Service systems
On the BDC, backup copies of the file servers holding
users' personal filespaces are taken at intervals, for
use in case of major hardware failures. Normally you
should make adequate backup copies on USB devices, CDs,
DVDs or ZIP disks (there are writable CD drives on most
BDC machines, ZIP drives on a few and USB connections on
all). It is advisable to keep two current copies as well
as routine backup copies.
Do not store data on the local hard disks (e.g. on drive
C: on a Windows PC) or the desktop on the BDC, as such
data cannot be guaranteed to remain available from
session to session, even on the same computer. Data that
you wish to keep should be stored in your BDC personal
filespace (drive U: on Windows), and backed up as
described above.
The ITCC message store has disaster recovery backups
similar to the BDC servers - that is, they are for
system recovery only. ITCC also keeps copies of deleted
email for limited periods of time so that in most cases
we can restore a user's accidentally deleted email. We
recommend that users keep their own offline backups of
their email, especially if they want to archive large
volumes of it.
Other networked systems
If you keep files on a fileserver in your College or
Department, you should ask your local computer support
staff what backup arrangements are made; they will
normally have provision for recovery from major disk
failures, for instance, but they may not easily be able
to retrieve individual files.
If you have your own equipment This section applies to any equipment for which you
are responsible, but is particularly vital for owners of
laptops. Every year there are instances of stolen
laptops which contain the only copy of someone's thesis,
essential papers or laboriously collected data.
You should always keep an up-to-date copy or copies of
any important data on USB devices, CDs, DVDs or ZIP
disks, stored separately (i.e. not being carried about
in a laptop case). See leaflet G81: CDs and other
removable storage media. "Important", in this context,
means anything that you would find difficult or tedious
to reconstruct - e.g. taking more than an hour or two at
most.
You may also want to consider whether the time invested
in the software setup and configuration of your computer
is such that the whole system bought to be backed up to
a mass storage medium such as CD, DVD, tape, secondary
hard drive etc. The cost of rebuilding your system after
a major crash (or setting up a new system after yours
has been stolen) may be very considerable for you or
your local Computer Officer or both. The Computing
Service can provide advice on backup devices and
strategy where local facilities or advice do not exist.
