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The
predominant strategy of backing up your data on your computer these days
seems to be no back up at all. The old adage, "ignorance is bliss" may just
come around to bite you in the ass like a rattle snake waiting in the tall
grass, that's your computer's hard drive.
Your
data is the least expensive component of your computer system, but it is
also the most valuable code inside your machine. Consider the overwhelming
if not impossible task of reentering all your important data in the event
your hard drive should become unreadable. Should your hard drive be rendered
an expensive paperweight, by the failure of any of the gazillions of parts
located within it's box, you will feel a lot calmer knowing that your information
has been safely archived, ready for immediate reentry to your system, when
it becomes up and running.
The
Drive Or Just A Short Putt?:
Hard drive manufacturers generously offer warrantees of three to five years
from the date of their manufacturing, and they will often replace it no questions
asked, within the warrantee period. This liberal replacement policy stems
from the fact that modern hard drives are the most reliable they've ever
been and the failure rate from todays top rated manufacturers is extremely
low. But don't let the statistics fool you. However astronomical, odds are
that someone will hit the lottery, some yokel from the sticks pops up on
the tv all the time several million dollars richer. The point being, while
there is every reason to rely on your hard drive to store your most valuable
data, the most likely component of your system to fail is the hard drive
with it's multitude of moving parts. The best thing to do is to believe that
your hard drive could fail at any moment, and back up your data religiously.
Little
Bumps And Big Crashes:
There are so many tiny parts working together in today's modern hard drive.
It's a wonder that they're as reliable as they actually are. A multitude
of things can go wrong which may result in lost information. Much of the
time these are minor problems which won't ever result in any problems at
all. Of the hundreds of thousands of files contained on your computer's hard
drive only a small percentage of these are mission critical files. If they
were to fail it would bring down your entire system. Even a smaller percentage
of the files on your drive contain your valuable data.
Data
on your drive is stored digitally, as ones and zeros, a whole lot of ones
and zeros. If any of the zeros are confused as ones or if ones are mistakenly
read as zeros, your files could become corrupt. On a magnetic media drive,
such as your systems hard drive, the ones and zeros are held as oxidized
and non-oxidized particles on the iron based substrate platter. If a strong
magnet acts on the magnetic substrate, data on the drive can be lost.
Let's
Chew The FAT:
The filing system is the way that the drive stores your files. Files are
divided up into chunks and distributed into clusters in random places with
enough room on your drive. The File Allocation Table or FAT holds the information
needed to put the files back together when your system calls for them. Sometimes
the drive's logic chips make a mistake and the FAT is wrong about the contents
of a particular file. Most commonly assigning too many clusters to a file,
but sometimes missing a few. When this occurs the file is said to be corrupted,
and the files integrity is in question. This is by far the most common type
of error associated with modern hard drives, and most of the time can be
corrected with software, with no lingering ill effects. Sometimes, however,
the files that become corrupt are critical to the operation of your system,
applications, or affects your data.
Occasionally
your File Allocation Table can be the thing that becomes corrupt. When this
happens, some or all of the information on your drive is rendered unreadable
because your system cannot put the files back together without valid FAT
information. This type of crash can be fixed with software, most of the time
by reformatting the drive, with a loss of some data of course.
The
Bump And Grind :
While storage problems can be blamed for many file corruptions, some come
from physical damage to the delicate platters that store the data. Todays
hard drive platters contain magnetic media surfaces of one molecule thick,
that spin at extremely high speeds. The heads that read the ones and zeros
float on a tiny layer of air above these defecate platters. If the heads
touch one of the disk surfaces, called a head crash, or a bump, it creates
a defect in the platter. If the drive tries to store data in that damaged
area, the data will become unreadable. This type of problem can be corrected
by software that identifies the damaged area and tells the drive not to try
and store anything in that area again.
It's
The Big One :
The last major type of disk problem is called total catastrophic disk failure.
As the name implies, this one is bad. We usually never find out the exact
cause of why the drive failed, just one of the umpteen hundred parts failed
somehow, which resulted in the drive not working at all, sometimes your computer
won't even boot to DOS with the effected drive plugged into the machine.
If you haven't done a recent backup, be prepared to spend hundreds of dollars
to have a qualified professional take the drive apart and hope that they
can recover some of your lost data. If you did back up, get a new drive,
reinstall your system and programs and recover your data from your back up...and
off you go .
I
Should Backup How Often?:
If you run a business, where your data changes constantly, backing up your
important data hourly may be sufficient. If you are a casual computer user,
your data may be sufficiently being backed up only once a month, or even
less. The rule of thumb is pretty simple, the more your data changes, the
more you should be backing it up. It's Murphy's law ( yup....it applies to
computers too! ) that the only drives that fail are the ones that aren't
being backed up. Now, I don't know exactly how that works, but I find that
most of the time it rings true, so if backing up your data can cause your
drive to never fail in it's entire lifetime, than it would be well worth
the effort.
So
What's To Backup?:
Many of the top back up utilities assume that most users want to back up
every file located on your system. Unfortunately, backing up whole drives
usually takes many disks and a whole lot of time, which leads users to under
utilize their backup systems. Once in a while these whole system backups
can be useful and save a lot of work, but more often they backup more stuff
then really necessary. If you feel that you need a full system backup, by
all means, do it. But do it, say once a year, or twice a year, and save the
backed up volumes somewhere safe.
The
majority of the backups that you should do should be quick and simple data
backups. Data being, the files that you create in your applications. If your
hard drive ever does fail completely, you have the installation disks for
your operating system and all your applications, or you can always buy new
disks. The only way to recoup your data would be to restore it from a backup
disk, or to (ugh) re-create it all. So your data is the most important thing
for you to be backing up. Get it? .... Now I would never advocate the mass
dumping of virus software. Just as it would be ridiculous for someone to
say I live in an area rarely affected by Aids so I won't use a condom. Viruses,
no matter how small and insignificant in numbers, do exist in the wild. There
are ways to keep your computer safe from the malicious exploits of some psychotic
hacker.
Backup
Your System Much?:
Just as was stated, automated full system backups, if you have the patience
and the disks are alright to do, but are seldom necessary or useful unless
you have a complete hard drive failure. If you run into any of the other
smaller hard drive storage problems, a configuration backup is more useful.
Windows 95 came with a utility called ERU, short for Emergency Recovery Utility.
This neat little self-contained utility can take a snapshot of your system
and save it. By running the recovery command from DOS your system can be
restored just as it was before you made any changes. (usually the changes
you made stopped your system from running properly, or at all!) If you are
running Windows 98, each time you shut down successfully, windows stores
a copy of your configuration files so that you can go back several shut downs
ago and restore the configurations automatically. Windows 95 on the other
hand, only stores the a configuration of the last successful shut down. If
you are lucky enough to own a copy of XP, your system creates restore
points every time you install non-certified hardware or software, and everytime
you shut your machine down correctly.
The
ERU utility however is the best way to capture your system configuration
files if you still run Windows98 and ( I shutter to think) if
you still are running Windows95. The utility can be run from DOS (not
a DOS prompt through windows), and that is all you get most times when your
system fails to load windows. ERU can be found on your Windows CD, put the
CD in the drive, and do a file find for ERU, then double click on it. Choose
other directory, because if you chose to save it on a floppy disk several
key files will be missing, because even in a compressed form they all won't
fit on a floppy. Store it in a folder in the default directory "ERD". The
folder should read ERD\XX-XX-XX ( the X's being the date, be sure to use
dashes, because slashes are unacceptable in WinDOWS based file and folder
naming).
Seen
1 Backup, Seen 'Em All :
The security and peace of mind that you get from backing up your drive can
be enhanced by backing up your system in increments. This constitutes a
multi-tiered backup, which could provide the ultimate security system for
your data. To achieve this Fort Knox approach you'll need a few extra disks.
The basic A-B system is fairly straight forward, make a backup one day, then
the next time you back up, put it on another disk, or set of disks. If you
accidentally make a mistake on a file, and don't discover it until after
you run your backup utility, you still have a backup version that contains
your original file, intact, before you messed it up.
Another
advantage to having multiple backup volumes is because removable disks are
more vulnerable to magnetic disturbances, spills and mishandling. Think about
how it would feel when your drive fails. You feel great, having backed up
your data onto an archive set, only when you reach for your archive, you
find that one of the disks is corrupt. All that time spent backing up your
system could have been better spent watching the grass grow. The savvy computer
operator would just put in archive B and not miss a beat, oh he might be
a week behind in his data, but that sure beats having to recreate all your
data. How long would it take you to recreate all your data?
If
you do a daily backup, why not label five disks each with a day of the week,
and rotate them. Or if you backup weekly try four disks, one for each week
of the month. Make your backup system fit your own individual needs.
Where
Are You Backing Up To?:
Your data can be backed up to another folder on your hard drive, or another
partition on the same drive. This strategy will work well if the problems
on the drive are small and only result in few important files become corrupt.
If the entire drive fails, the backup will also be lost.
If
you're lucky enough to have two hard drives installed in your system you
can backup one drive onto the other, more or less mirroring one drive to
another. This type of system can be very useful especially in a business
situation, where down time for a PC can be measured in lost revenue. If the
primary drive goes down it would take about five minutes to get the system
up and running, most of which would be consumed in trying to open the case
and switch the jumpers on the drives.
The
dual mirrored system is pretty secure. The chances of both drives going bad
independently, at the same time, is very slight. However, it should be mentioned
that there are some set of circumstances where both drives would be subject
to loss at the same time, in the same machine. These would be fire, flood,
theft, damage due to mishandling, and of course electrical power surges including
lightning strikes. Due to this slight threat, even a dual mirrored drive
system needs to be backed up to another source, if only occasionally.
The
vast majority of home and small office computers contain only one drive.
For these systems it's necessary to back up to some form of removable media
or to another computer on a network. If you have over ten meg of data (the
files that you made in your applications) using the old standard 1.44meg
floppy disks can get a bit cumbersome, and time consuming. Also, if one of
the disks goes bad, most times you can't access the entire back-up volume,
thus effectively increasing the failure rate of your backed up information
(eek!).
So
the obvious solution is to get a removable media drive that is large enough
to hold your entire backup set on one or two disks ( it has to be on one
disk to do an unattended backup, or else you will have to change disks in
the middle). When considering a removable disk drive remember to consider
how fast your data grows, and to always allow capacity for future increases.
With Cd recordable and re writable drives coming down in price, these can
be considered as a good choice for high capacity backups. Remember that CDs
are unaffected by magnetic disturbances. If you have a lot of data, one or
two gigs or more, or still feel that you must back up your entire drive,
a tape back-up can be considered. They are slow and can be time consuming
to restore files, but for capacity they really can't be beat.
You
should also remember that a backup volume in the same room as your computer
would be subject to the same conditions, such as fire, flood or theft. This
being said, a copy of your backup stored on a different site as your computer
could come in handy in case of some unforeseen circumstances. There are a
few different services that will store your data on their servers over the
internet, which could alleviate the problem of storage space constraints
as well as providing a secure off site storage solution.
Backing
up your data simply cannot be overlooked these days.
Got
more questions?
.........Click
here to ask us!
...continued next
month.
*Rich
Lipsky is the owner and operator of ComputerHelp911.com, a local company
that specializes in solving computer problems for local residents and businesses
since 1995.
Rich is available for questions, or for
consultation. You can reach him at:
(315) 382 - HELP. |
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