Everybody should have an off-site backup of their data. Off-site backups are good protection against fire, floods, burglaries, earthquakes and similar events. These are rare events, but over the past 20 years, I’ve seen all of these events occur and affect client data.

As you design your backup system keep in mind the primary 3-2-1 rule. You should have 3 copies of your data. The original plus 2 backup copies and 1 of the backup copies should be off-site.

The two most common types of off-site backups are a Time Machine backup stored on an external drive and a cloud-based backup. There are pros and cons to each of these. Personally, I use both of these as off-site backup systems.

I have two external backup hard drives. Every Sunday I take one of my hard drives to my off-site storage location which is a few blocks from my home office. I drop off the drive and pickup the drive that has been sitting safely off-site for the past week. I bring that drive back to my home-office where it’ll become my active drive. I’ll use it to store backups made by Apple’s Time Machine. Then, at the end of the week, I’ll drive this hard drive off-site and begin the process again.

I also subscribe to a cloud-based backup service, CrashPlanPro. You can also use CrashPlan for personal backup. Collectively, I’ll refer to these two related services as CrashPlan. CrashPlan is a cross-platform cloud-based backup services. It supports Mac OS, Windows and Linux. CrashPlan, and all cloud-based backup services are only able to effectively backup user data, such as email messages, PDF files, JPEG files, Word files, music, etc. In other words cloud-based backup systems can’t effectively backup your computer’s operating system or applications. This is in contrast to Time Machine which can backup the Mac operating system and applications.

Another important difference between Time Machine and cloud-based backup systems, like CrashPlan, is the amount of Time needed to complete initial backups and/or restore data. For example, if one has 100 GB of stuff on his or her Mac’s internal hard drive, Time Machine could copy all 100 GB onto an external hard drive in a few hours. Cloud-based backup systems would need at least several days and possibly a week or even several weeks. The amount of time would depend largely upon the upload speed or one’s Internet connection.

Similarly, it can take much longer to restore a lot of data from a cloud-based backup system, like CrashPlan, compared to the time it takes tor restore data from Time Machine. This is why I recommend that everybody use Time Machine as their primary (on-site) backup system. If you have the discipline to manually swap hard drives and thus create an off-site Time Machine backup, that is ideal. If you do not have the discipline to create an off-site Time Machine backup, or even if you do, I think a cloud-based backup system, like CrashPlan is a good secondary backup that’ll create an off-site backup.