Step 3: Choosing Backup Strategies
There are a number of different methods which are used to backup data. Without
the proper information it can be difficult to choose between the many options.
We will go over a few of these options here and try to provide you with
positives, negatives and our suggested Best Practices. Here is a list of the
five questions we will answer in this section.
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What type of backup should I use?
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How should I send my backup data off-site?
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Do I need monitoring?
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Should I use encryption?
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Should I use compression?
What type of backup should I use?
There are, as was briefly mentioned above, essentially three type of backup.
These are full, incremental and differential. Let's briefly define these terms
before we move on to recommendations.
Full Backup - This, as the name suggests, fully backs up all the files you
have selected for a given backup job.
Differential Backup - This backs up each file that has changed since the
full backup was created.
Incremental Backup - This backs up only those files that have changed
since the last incremental backup.
Now, full backup is pretty straight forward. This type of backup should be the
first one you run when starting a backup program. For those with very little
data or data that rarely changes, this may be the only kind of backup you need.
However, if you have many large files and/or your data changes frequently,
running full backups could quickly eat up your hard drive space. In this case,
you probably will need to run one of the other two backup types.
Differential and Incremental Backups are slightly more difficult to understand.
Both are designed to conserve space by limiting the number of duplicate files in
backup storage. Incremental backup results in less duplicates by only backing up
the files that changed since the last incremental run, but restoring an
incremental is more complex as each backup job will have to be restored along
with the full backup. Differential, while creating a few more duplicate files by
backing up all files changed since the full backup, is easier to restore since
only the last differential and the full are needed to return the latest version
of the data.
For instance, say we have four files that are backed up on day 1 as part of our
Full Backup and we choose to back up incrementally.
Now, if files one and two change before the first incremental backup runs on
day two than those two files and only those two files will be backed up.
Then if file three changes before the incremental backup on day three than
that file and only that file will be backed up on day three.
In order to restore from this backup you would need all three days worth
of backup files.
Now, if we have the same situation and we choose to back up
differentially it would look like this
Again, files 1 and 2 change before the differential backup runs and they are
saved in the day 2 backup file.
Then, before the day 3 backup runs file three changes. The differential
then backs up files 1, 2 and 3 because they have all changed since the
original full backup.
To recover from the differential backup you only need the full backup
and the last differential. So, Day 3 and Day 1 will get us back to the
most recent files.
For most users running an occasional full backup and regular
differentials provides the right balance of storage space conservation
and ease of recoverability. Incremental is only recommended for those
with very large files undergoing constant change.
How should I send my backup data off-site?
Notice that we aren't asking
if you should send your backup data
off-site. The question of whether or not your data needs to reside in a
safe alternate location was answered earlier when we asked, "What are
the potential results of losing that data?" If you answered fatal, major
or even minor for any of your data types, you should send you data
off-site.
There are a variety of methods for moving data off-site. We will walk
through the most popular methods and look at some of the positives and
negatives for each.
Portable Media
Backups are made to CD, tape, external hard drive, etc. and then
transported, often by an employee, to a secure off-site location.
Pros - Relatively simple, commonly used, allows for quick restore
(as long as the storage location is nearby)
Cons - Possibility of human error, transport is often a security
concern.
Online Backup
Backup files are uploaded via the Internet to third party storage
servers.
Pros - Easy to use, relatively affordable, no need to maintain
storage facilities or buy equipment
Cons - Files can take a long time to restore (depending on
bandwidth and file size), some security concerns as data resides with a
third party.
Does my backup need to be monitored?
Yes, automated backups are notorious for going wrong due to inattention.
Often backup errors go unnoticed until an attempted recovery at which
point it is too late. Every backup job should be monitored on some
level, either by a third party monitoring center that tracks and reports
errors or by an in-house technician that reviews the backup log files
each morning.
Should I use encryption?
Encryption puts files into another format (like .zip) and password
protects them so that they are impossible to access without the
password. This adds a significant level of security to your backup
files. However, if you lose the password, the files will be
unrecoverable. Also encrypting files has some risk of corruption which
can render files unreadable.
If you have serious security concerns, encryption can be a useful tool,
but if possible, we recommend using other methods to secure backup data.
For instance, hard drives receiving back up data should be placed in a
secure, limited access location. Also, windows has tools that will allow
you to control access to the backup files.
Should I use compression?
Compression is
only necessary if . . .
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Disk space is a concern.
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Backup files are being stored on CD, DVD or other media
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Files are being sent over LAN or WAN
Compression will considerably slow the backup process. The more
compression, the slower the backup. Also it will reformat the files thus
possibly complicating recovery. Compression should only be used if
absolutely necessary.
Wrapping Up
OK, you say, I have a good grasp on my backup needs and I want to get a
solid backup program in place. Well, the next step is to choose a backup
software.
But, we aren't here to make a pushy sales pitch. We are here to help you
with your backup program. So, if you have any questions about this
document, backup in general or any suggestions of other topics we should
address, please contact us at 610-352-1150, through our online forum at
support.universepoint.com
or email
support@universepoint.com.
If you would like to try out ION you can download a
free trial and see what we are all so excited about.
Sincerely,
The Universe Point Team