| The focus here is on a
Data Recovery
Plan, because in the end, hardware can be replaced, but
lost data usually can't unless precautions have been
taken first! The only real insurance against data loss is
a backup procedure which is followed in a regimented
fashion. You can rely on some system's capabilities to
undo file deletions, or to recover damaged hard disks
through sophisticated file copying redundancy, such as is
found in RAID (Redundant Array of Inexpensive Drives)
systems featured on more costly network servers, to a
certain extent. Your action plan, however, must allow you to be able
to recover from a Level V disaster to be worthwhile. A
regimented backup procedure requires four elements in order to be
worthwhile:
- A backup device which is reliable.
- Backup media which has sufficient
capacity to store all required information, both in terms of
server and operator data.
- Backup software, or methods which
allow quick and easy recovery of damaged or lost files.
- A set of procedures which ensure
both sufficient redundancy in backup to recover data that may be
lost for some time before the need to recover is
identified, and yet is secure enough to withstand
a Level V disaster.
Each of these four elements are discussed with
specific suggestions below.
Backup Device
 The device you choose to backup
onto is crucial to your success in surviving a systems
disaster. Picking a backup device which is unreliable is
worthless. Backup devices are varied, so you need to
select one which fits your requirements. A simple option
is a device such as a Zip drive which can utilize 100MB or
250MB disks. This solution can cost you under $150,
including media. Another solution is larger removable
media, such as portable hard drives or Jazz type drives.
Yet another solution is a tape backup system which can
hold 12GB or more of data. Mendon Associates Inc. uses a
DAT tape backup system due to the speed, portability and
low cost of the media.
Whichever device you choose, make sure that you can
obtain a backup for it too. If you have a single old
cartridge backup system, make sure that if it were
damaged or stolen, you could replace it quickly. If the
system is so antiquated that you can't obtain a
replacement, then your backup tapes could be worthless.
There are service bureaus that can read most media for
you, however, ideally you want your backup solution to be an
exclusively internal one to your company. For this
reason, it is recommended that you upgrade your backup
device as you upgrade systems, especially servers, in order to
ensure that you have the latest devices which can be
readily replaced.
Whatever you choose for backup purposes, test it on a
regular basis to ensure that it remains reliable. If you
are using a tape drive system, clean the heads
periodically as per manufacturer's recommendations.
Equally important is the location of the backup device.
Generally speaking, installing it on the server is the
preferred method. Wherever it is set up, make sure that
it is configured to be able to back up all systems which
contain crucial data. If you cannot see some of your
operator's hard disks, make sure that they are backing up
individually, or only store data on the server's hard
disks. Backup Media  The media you select
should be
portable so that it's easy to store. Equally, it should
have sufficient storage capacity to hold all of your
data, preferably without needing to use multiple volumes. As
with devices, media can degrade over time, so periodic
testing is a vital procedure which should be part of any
backup regime. If your backup software has a verification
option, where it checks the data stored on the backup
media against the data on the network for comparative
purposes, always use this feature. Replace media
following manufacturer's recommendations for expected
life spans.
Above all else, keep you media away from
magnets!! Many paper-clip holders use magnets, so storing
tapes near or around these holders can put them at risk
too. As well, store the backup media in a secure location
away from the server or backup device!
Backup Software/Method The software you select will determine how
sophisticated you can be about backing up. Some software
allows you to select specific drives, directories and
times for backing up. If you are using a disk type of
backup, you could use your system's simple copy commands to
copy from the source to the target drive. If you have
Windows 95, 98 or higher, there is a backup utility which comes
with the operating system that also does file compression, which allows you to get more onto a disk. It also allows you
to verify data as mentioned above. Windows NT Servers
also come with backup software which will recognize most
popular drives and has verification features as well.
These packages also have simple restore procedures
which allow you to restore all or some files from a
backup media.
Backing up is a monotonous and boring task, but it is
a crucial step to ensure your success in surviving a
systems disaster. For this reason, we strongly recommend
that you purchase software that has built-in script
writing capabilities and which can be timed to start
independently. In this case, all an operator need do is
replace the media every morning.
Backup Procedures Setting up your backup procedures to ensure that you
are covered in case of an emergency is important. It is
too easy to fall out of good backup habits, so whatever
you decide to do, write the procedures down and re-read
them on a regular basis to remind yourself what to do, or to make
changes to them, if necessary.
 It is a mistake to backup onto
the same set of disks or tapes every time. Often if a
file is removed, it is not noticed for some time, so
backing up onto only one set of media is not sufficient.
There are tens of thousands of users out there who have
purchased a sophisticated tape back up system, but only
one tape ― this is nothing more than a disaster waiting
to happen! Some users have three sets of media that they rotate
through, but even this is not good enough.
We recommend
as a minimum, an eight tape system, where you have one
tape designated for each of Monday through Thursday, and
four tapes labeled "Friday I" to "Friday
IV". In this way, the Friday tapes are rotated so
that you have individual backups for each of the last five
days, and for each of the last four weeks.
As a further precaution, and in order to meet the requirements
of a Level V disaster, Friday IV tapes/media are sent
off-site in a rotation of three tapes marked for Friday
IV-A to IV-C. The Monday through Thursday tapes are
replaced with new tapes annually, while the Friday tapes
are replaced every other year. These old tapes are used
for one-of backups, such as when large project
directories are removed from one of our servers, as a
permanent record. Note that the verification option of
our backup software is always set to on. Some clients
rotate one tape every month permanently out to an
off-site storage facility. Given the low cost of tapes,
this is an inexpensive form of data insurance.
Backups should be done daily, and should be timed to
happen at the lowest point of usage on your network or
systems, which is generally at night. All backups should
be verified every morning, and backup tapes or disks
replaced at that time with the next one in sequence.
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What would happen to your business if you
lost your computers and the data on them tomorrow? How
dependent are you on your systems? To find out, do a
simple systems usage survey. Go to each computer in your
organization and ask the operator the following questions: