I am absolutely fanatical about taking backups. I have
hundred gigabytes of data that's really important to me, some, like
photographs are irreplaceable, while other things like source code,
artwork, purchased software, etc... can be replaced, but not without
considerable effort or expense. Since most computers store their data
on hard discs, and since hard discs have moving parts, failure is
inevitable, at some point.
I have a lot of computers, and since I don't want to
of my time moving files between them on USB drives, I've setup a
central fileserver I can access from anywhere in the world. This
simplifies backups a little, since all of the important files are in
one place. If you plan to do this, I suggest you build in as much
redundancy as possible and take regular backups, since the fileserver
becomes a single point of failure.
Redundancy is important
In my system, I have two very reliable (server grade)
Ultrastar 1.0TB discs mirrored together in what's called a RAID-1
configuration. Both discs behave as a single virtual 1.0TB disc, and
everything that is written to this virtual disc is copied to both
physical discs. Even if one physical disc fails completely, no data is
lost. This still presents a problem, since you're still using hard
discs, and there's still a chance that both could fail simultaneously.
Some circumstances where a mirrored set of two or more discs could fail
include natural disasters like floods, tornadoes, and earthquakes,
electromagnetic pulses from solar flares and damaged power lines, power
supply failures, fires, and water leaks. Even if both discs continue
functioning indefinitely, there's a chance that malfunctioning software
or a mailcious intruder could delete sensitive files. It's also highly likely that a user will
accidentally delete an important file at some point.
The best solution to all of these problems is to use
of removable media. If your data is really important to you, I suggest
you make multiple sets of media and keep one set offsite. What type of
media you use, what format you store your backups in, and how often you
need to make backups are all things that you will need to decide for
yourself, but I'll try to help you make the right decision.
If you only have a small amount of data, say less than
cheapest and easiest way to go is to use optical discs. They're cheap,
relatively reliable, supported on every platform, and don't take up
much space. Since the media isn't part of the drive, it can be more
reliable than a hard disc. The biggest advantage is their ubiquity, you
shouldn't have a hard time finding a machine capable of reading optical
discs for quite some time.
Please keep in mind is that, for the most part,
optical discs are not an
archival storage medium. Optical discs are made from several layers - a
polycarbonate disc, a laser-light sensitive dye, a vacuum desposited
layer of aluminum, and a protective coat of lacquer. Over time, the
lacquer layer can separate, the dye, which is the layer containing the
actual data, can fade, and the aluminum coating can oxidize.
Commercially prepared discs are immune to some of these problems, since
the bits are pressed directly into the plastic rather than written by
A standard grade CD-R or DVD-R will usually have a rated
archival life of around 5 years. For system snapshots this should be
OK. In terms of commonly available discs, I recommend Emtec, Fujifilm,
JVC, Pioneer, and Ritek. Stay away from brands manufactured by
Infodisc, which included Memorex the last time I checked. If you have
data that needs stored on a longer basis, but you still want to use
optical discs, I suggest you buy a finer quality of disc, such as
Mitsumi's MAM-A formulation, which is rated for 20+ years. Regardless
of what type of disc you use, you can prolong their life by
keeping them in black plastic cases, in a low humidity environment, and
from sources of heat and UV radiation such as sunlight and fluorescent
Good quality CD/DVD drives are relatively inexpensive,
typically costing under $200 depending on options. I suggest you go
with the highest quality model you can afford, since you'll need it to
be there for you when all else fails. I would highly recommend TEAC,
Plextor, Samsung, and Panasonic drives for their highly reliable
service and good performance. Compression tools like WinRAR can be used to increase the
amount of data you can fit on a disc library, and can even split
compressed archives into 700MB or 4.38GB for writing to CD or DVD.
Tape is sort of the gold standard for backups. Like
discs, they have the advantage of the media being physically separate
from the drive. They're small, fast, highly reliable, and are much more
practical for large volumes of data than optical discs. Tapes can be
used for archival purposes, since most tapes come with a lifetime
guarantee and are rated for a 50+ year archival life. The only drawback
is initial cost, which can be higher than optical discs.
Wading into the deep pool of tape drives can be
intimidating, since there are a variety of tape formats. In my opinion,
the best system for workstations is DAT, which is also called DDS or
4mm. It uses the same type of cassettes used by high-end audio gear in
the 80s/90s (DAT stands for digital audio tape), which are very small,
about half the size of a compact cassette and at the time of this
writing hold up to 80GB.
Tapes and their drives are usually referred to by their
capacity, the original DDS-1 tapes from 1990 were the same
capacity as the audio tapes, 2GB. All DDS drives have hardware
compression, so when referring to a tape's capacity, the manufacturer
usually lists the tape's capacity for text data, which is twice the
native capacity. Data that's already been compressed, like JPEG images,
MPEG videos, and zip archives won't benefit from the compression, and
will take up about the same amount of the space on the tape as they do
Here's a list of the currently available generations of
DAT/DDS tapes and drives
New tape drives usually cost a few hundred dollars,
fortunately older drives are usually available for very little. I
bought a DAT72 drive on eBay a while ago for $30. Tapes for DAT drives
are usually fairly inexpensive, less than $20 each at retail prices for
the current generation, and significantly less if you're a bargain
hunter. In general, DAT drives are backward compatible, so if you
upgrade you won't need to re-write all of your archives, and if you
only need to store a small amount of data you can use a cheaper, lower
To get the maximum lifetime from your tapes, try to
somewhere away from high temperatures and humidity, keep them in their
platic case, and do not expose them to strong magnetic fields. Other
than actual magnets, sources of magnetic fields can include electric
motors, soldering irons, CRT displays, and electrical transformers.
I personally would not want to depend on a hard disc for
main disadvantage is the reliability. Since the media is part of the
drive, if the drive fails, the only way to recover the data is to send
it to a company that specializes in recovering data, which is almost
always an expensive proposition. The advantages of using a hard disc
include low cost and speed. If you have very sensitive or important
data I strongly suggest that you save it to removeable media, although
it's perfectly acceptable to use a hard disc for taking system
If you plan on using a hard disc for your primary
using a RAID configuration. Even if you don't have a hardware RAID
controller, most operating systems will let you setup a virtual RAID.
In Windows you do this through the Administrative Tools section of the
Control Panel. The backup disc should be physically separate from your
primary disc, never use another partition on the same disc as a backup.
Using an external USB or eSATA drive removes the hazard
power supply failure causing damage to your backup disc, but only if
you leave it unplugged while you're not actively using it. Handle the
disc very gently, do not expose it to high levels of moisture, heat, or
vibration. Hard discs should be kept away from strong magnetic fields.
Other than actual magnets, sources of magnetic fields can include
electric motors, soldering irons, CRT displays, and electrical
This has been an emerging trend in the last few years,
several companies offering free and paid online backups. The biggest
advantage to this is that all of the data is stored offsite, so natural
disasters, local hardware failures, fires etc... will not destroy your
data. The biggest disadvantage is that you're entrusting your data to
an outside entity who may or may not be reliable. When shopping for a
remote backup service, there are several things you should consider.
Where are their servers located? Are you comfortable with your data
being stored overseas? What kind of hardware do they use? How regularly
do they backup their hardware?
How is the data transferred from your computer to their servers, and is
it securely encrypted? Who will have access to your data once it's
stored on their servers? Since their servers are connected to the
internet, they should be rigorously secured, since the consequences of
a malicious third party gaining access could be astronomical. Most
importantly, will the company still be around a few years from now?
Tech company buyouts happen constantly, so it would be best to stick
with one of the larger companies like Microsoft, Amazon, or IBM that is
unlikely to disappear overnight.
The most reliable companies will have privacy policies
detailing who and under what circumstances a third party may access
your data. Regardless, if you must use online backup, I suggest
encrypting any sensitive data before you upload it to
their servers. I would also suggest you avoid Google, since they have a
One last thing you may want to consider is that in the
of a natural disaster you may not have reliable internet access. Keep
local copies of anything you might need in such a circumstance.