Date: November 30, 2004
Subject: Protecting Your Data
I would
like to begin this month's bulletin by asking you three questions:
1/ How
is your data protected against theft of your hardware?
2/
What would happen to your data if your computer stopped working?
3/ How much money would you lose if you were unable to
access critical data?
My point in asking you these questions is to emphasize how
important the data on your computers is to the survival of your
organization. Many readers of these bulletins have a data backup system in
place but for those of you who do not I would like to ask a fourth
question:
4/ What is keeping your data from being completely and
irretrievably lost?
Cost of backup vs. cost of data loss - What
is often overlooked when computers are purchased and maintained is that
the value of the data on a computer system will eventually exceed the cost
of the system itself. While great pains may be taken to obtain the most
reliable system with the finest warranty quite often a much smaller amount
is allocated to the proper backup of the data that will be stored on that
system.
Two principal arguments show that the cost of an adequate
backup program is much smaller overall than the value of the data being
protected:
1/ Creating and maintaining corporate data requires a
significant investment of time and labour, a similar investment of time
and labour would be required to recreate this data should it become
inaccessible or lost.
2/ Your data also has a great deal of internal
value in terms of cash flow, client and contact information, development
plans, etc. Imagine the cost that would result in the event that billing
information or contact information for vital clients is not available.
Ten Tips to an Effective Backup Procedure -
I would like to list for you ten tips that will help you to
establish and maintain an effective backup procedure:
1/ Decide what to backup - Depending on your
circumstances it may not be necessary to backup all data and software on
your system. Systems such as network servers should have a complete backup
on a regular basis. Systems such as workstations may only need to backup
various user modified files on an occasional basis. An understanding of
the difficulty involved in recreating any lost data will be the most
useful guide in determining the amount of data to backup.
2/ Decide when to backup - Make
a schedule and stick to it. This schedule will be largely determined by
the frequency at which your data changes but in general a daily backup of
regularly modified data and a weekly backup of all data will be adequate.
3/ Maintain multiple backup sets - Have at least two
sets of backup media and rotate them on a regular basis. For many of our
clients we recommend that they use a monthly rotation of backup media
for daily backups operating in parallel with a semi-annual rotation of
backup media for weekly backups, as well as an annual (or longer) rotation
of backup media for monthly backups. For other clients we recommend that
they use two sets of backup media that are rotated every other week. In
either case there is the advantage of added security as well as the
reassurance that existing backup sets will not be overwritten by new
backup sets and causing both backup sets to be destroyed if something goes
wrong.
4/ Backup before updating - Prior to any major system
upgrade, such as the installation of a Service Pack or Security Update, it
is recommended that you perform a full backup of the system being updated.
Some will go so far as to recommend a backup before installing any
software but in most cases this is excessive. The reason for this is that
if the installation goes wrong or the power fails at a critical moment you
will at least be able to restore your system and get back to work in a
relatively short period of time.
5/ Use overlapping backups - In a networked
environment it is possible to backup to a remote hard drive as well as to
the regular backup device and to use a different backup method in either
case. The advantage of this practice is that if it becomes impossible to
restore from one backup it may be possible to restore for the alternative
backup.
6/ Delegate responsibility - Assign the responsibility
for the backup to one individual in your organization. Ensure that they
know to check that the backup has run as expected and to switch backup
media as necessary. It would also be advisable to designate someone who
would be able to cover the primary individual during vacation and sick
time.
7/ Maintain a log - Use a log to monitor your usage of
backup media. This log should be used to determine when to overwrite
backup media as well as showing which media should be used next. You can
also use this log to note any errors with the backup for future analysis.
8/ Save a backup offsite - Storing your backup data in
the same facility as the original data may be convenient when individual
files need to be restored but can be disastrous in the event of the
destruction of that facility. It is a good practice to rotate at least one
relatively recent backup to an offsite location so that data may be
protected from most hazards.
9/ Read the reports - Most backup programs create a
report of what has been included in the backup, what has not and what
errors may have occurred during the backup. On a regular basis examine
these reports to confirm that the backup is running as expected. In doing
this you might also catch minor problems before they become more serious.
10/ Test your backup - It is not good enough merely to
view the status reports of whatever backup system you choose as these
reports only inform you that data has been processed but do not test if
the data can be restored. At the very least select a single file out of
your backup and attempt to restore it in order to confirm that data may
also be retrieved. For further assurance you should also test your backup
on a quarterly basis.