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Choosing backup storage format
The simplest approach is to store each file in the backup copy as is. In many
cases this may be the best choice and you really don't need to think about
anything else. However let's take a look at other options and benefits that
they may give. Basically you can do two things:
 Compress data;
Encrypt data.
Compression. When you apply compression you save storage space and
network traffic in case you need to transfer backup copy over network. If
your network connection is relatively slow, you can also save time required
for backup. On the other hand the compression is an additional process that
requires time itself, so you may loose time as well. So, the decision is usually
made depending on the type of your data. If you backup pictures, mp3 or video
files, archive files or any other data that can't be compressed with a good
ratio, it is better not to apply compression. You will possibly loose more
than you gain. However compression is efficient for text and HTML files, MS
Office documents and other similar files.
 Most
compression utilities and some backup programs will allow you to choose compression
quality for stored data. The higher is the compression quality, the more time
will be required to process the data, but the resulting file will be smaller.
ZIP is the most common format for compressed files. Average text data can
be compressed to 20-30% of the original size.
Encryption. If you want to protect the backup copy from unauthorized
access you should encrypt your data. Various encryption methods provide different
security levels. This does not mean that you should always choose the highest
level. If you don't expect that a well skilled hacker or a person from a special
security service will try to decrypt your data without your permission, you
should probably choose encryption method that is most easy to use.
ZIP file format allows you to protect compressed data with a password. This
is the easiest method.
The benefits are:
It
is very fast.
It stores your data in standard ZIP files, so you can extract it using any
ZIP client.
There are two weak points.
Security level is relatively low.
Anyone will be able to see the content of the archive, i.e. names of original
files and folders stored inside. Only the content of files is encrypted.
If you really need a high security level, you should use better encryption method like Blowfish algorithm. Unfortunately there is no standard file format supporting this type of encryption. Also, usually advanced methods require more time to process data, so if you need to encrypt a large amount of data, it can slow down the process.
No matter what method you choose, you should use a good password, store it
separately from your data and never tell to anybody.
Compatibility. Some backup programs use their own file format to store
backup copy of your data. They usually place the whole data in a single file
that can be compressed and encrypted. Such approach can be efficient, however
you should always remember that you will only be able to restore your data
using the same software. This may be a problem if you need to restore data
using a different system where that software is not installed. We already
mentioned above that if you use a standard file format, such as ZIP, you can
restore your data using any ZIP client.
Single file vs. many files. Depending on your needs, you can choose
either to compress each file separately, or put all files into a single ZIP
archive. If you want to perform incremental backups adding only new and changed
files each time, it is not recommended to put all files into a single ZIP
archive, because it is impossible to insert new data to an old ZIP file. In
this case the backup file must be fully rebuilt each time. So, you should
better use compression into multiple files instead, i.e. ZIP each file.
However in many cases incremental backups are not used, for example if you
store several versions of your data in the backup copy. In this case single
archive file is preferable. Joining many files into a single archive saves
space not only because of compression. If you have thousands small files,
they require significantly more space when you store them separately.
Even if you backup to CD or DVD media you still can put many files into
a single archive, because many backup programs support disc spanning to
split large backups. If your backup set contains large files with size exceeding
free space available on a single disc, the program will split such files
into several parts and place them on several discs.
Note that some programs can do incremental backup even when they store the
backup copy in a single file of a special format. However this approach
makes this file grow rapidly. It is applicable only if you have large amount
of data and at each backup the changes are very small. In any case you will
need to make full backup from time to time.
Conclusion. Your choice of storage format mostly depends on the type
of your data. If you need really good security you should choose good encryption,
even if this results in a data format specific to your backup program. In
any case you should make sure that your program can restore files from the
backup copy even on a different system, or after full system reinstall. If
your data can be compressed efficiently, you can apply compression. Finally,
if you have a choice between keeping all backup data in a single file and
storing each original file separately, you should choose depending on whether
you need an incremental backup or not.
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07.08.05
Backup Platinum successfully passed
the "Designed for Windows XP" certification
by Microsoft®
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Can run in service mode
on Windows 2000/
