Online Backup Recommendation

With the abundance of high-speed Internet connections, many individuals and businesses are considering online backup solutions, also called remote backup.

To find the best solution for clients and for my own personal use, I have reviewed a large number of online backup services and tested several. While there are a number of good solutions, I chose MozyHome for personal use and MozyPro for businesses.

Why Mozy?

When trusting data to an online service, security of the data is paramount. All backup solutions offer encryption to secure your data in transit and in storage. However, according to a May 2008 study, Mozy is one of the few that protects the user from a certain type of "man in the middle" (MITM) attack. An excerpt from the Heise Security article:

Only Carbonite and Mozy noticed that the certificate provided during a MITM attack was forged and refused to connect to the fake server. But only Mozy provided valuable information and warned users that they may be under attack.


Reasons why I chose Mozy:

  • Easy to install, configure, and use.
  • Well integrated with Windows Explorer.
  • Flexible automatic backup scheduling.
  • One of the most secure online backup solutions.
  • Backed by a large, well established company (EMC, originally).
  • Very inexpensive; 2 GB free for personal.

Mixed Reviews

I should point out that there are many mixed and negative reviews of online backup services on the Internet, including Mozy. From having worked in-depth with Mozy, I feel that the negative reviews are mainly due to individuals using Mozy in scenarios that are not ideal for online backups, not spending enough time to tweak the service, not having enough free space on the hard drive, or problems caused by other software, such as overly-aggressive firewalls.

In other words, Mozy is a highly-reliable backup solution, if you are willing to spend a little time configuring it and understand the limitations of online backup (see below).

Advantages of Online Backup

Regardless if you are a business or an individual, your data files are the most valuable part of your computer system. Here are some of the advantages of using online backups compared to traditional backup methods such as tape and disk:


  • Backups take place automatically.
  • Data is stored off-site where it is protected from fire and other catastrophes.
  • Data can be restored from any Internet-connected computer.
  • Strong encryption is used to transfer and store your data.

Limitations of Online Backup

Here are some situations where online backup may not work well or may require additional backup methods:


  • Online backups require a fast Internet connection. The upload speed of your connection must be sufficient to support the transfer of daily changes. For most households, a cable or DSL connection is sufficient.
  • If you are backing up very large individual files that change frequently, the upload speed may not be sufficient to back up such files nightly. For example, if your files are 10 GB in size, your Internet connection may not be able to handle it. For businesses with very fast connections, this may not be an issue.
  • If you are backing up a very large number of files, the backup software may run out of resources and hang. I have seen a case where a machine with 880,000 files was not able to make consistent backups.
  • Mozy is not an archiving solution, nor are most other online backup services. In other words, if you intend to remove files from your computer, but want to keep them as archives, you will need to use tape, disks, or other media to accomplish this.
  • Online backups are not meant as a complete system restore. While they are able to back up most files on a computer system, if a complete crash occurs, you must re-install Windows at a minimum, before files can be restored from Mozy.

Mozy Tweaks

For many desktop PC's, the default Mozy installation will work well without any tweaking. At times, some tweaking will be necessary for smooth operation.

Temp Folder

Before sending files to the online service, Mozy has to encode the files locally on the hard drive. To do this, it needs enough free space to hold at least 130% of the largest file to be backed up. For example, if the largest single file you are backing up is 500 MB, the hard drive needs at least 650 MB free space, and ideally more.

If your computer has a single disk and you are short on free space, the only option is to delete unneeded files.

If your system hard drive is low on free space, but you have other hard drives, follow these steps to instruct Mozy to use a Temp folder on a drive with more free space:


  • Create a "Temp" folder in the root of the drive with the most free space. For example, E:\Temp.
  • If you are not familiar with making registry changes, follow the Changing the Location of Temporary Files article on the Mozy support web site.
  • If you are familiar with making registry changes, modify the following entry with the new temporary path:

    HKEY_LOCAL_MACHINE\SOFTWARE\mozy\options\tempdir

    Note: For best results, enter only one path in the above registry entry, removing all others.

Connection Errors

Mozy relies on the underlying operating system to determine if it has a connection to the backup service. Occasionally this test fails and Mozy reports a connection error, even though the connection to the Internet is working.

If you have an always-on Internet connection such as cable or DSL, check the following configuration option to avoid this error:

Settings › Options › Scheduling Tab › Attempt automatic backups even if network connection is not detected