Backups

External Media Devices

Over the past decade, new technologies have made data backup solutions available to everyone. The more common media used today are the following:

  • CD-RW/DVD – This media is reasonably inexpensive and has the capacity of holding between 700MB to 8.7 GB of data depending on the type of disk and the type of burner in the host machine. Data backed up using this type of media should be static and properly handled to prevent data loss.
  • Flash Drives – These devices come in sizes ranging from a couple megabytes to several gigabytes and are best used for transporting files between systems. One drawback to this type of media is that its small size increases its potential of being misplaced.
  • External Hard Drives – These devices are best suited for large backups and can even be setup to backup the entire operating system. In many cases, software can be purchased with this type of media to help manage and schedule backups process.
  • Cloud-based storage – This type of storage is best suited for temporary backup of documents similar to that used on flash drives; however, cloud storage allows the flexibility of synchronizing documents across several devices without the name of a physical device. Currently, UIS supports eDocs (private storage) and Box (public storage)

Best practices

In an enterprise environment, backup systems consist of many methods (full, incremental, differential), media types (primary or secondary), and locations (primary or secondary). The problem is how to translate this type of model into a home environment.

Definition of terms

  • Full backup –This is an archive copy of all files and folders on the system. Without the use of differential or incremental backups, all changes made on the system since the last full back up will be lost.
  • Differential backup – This is an archive copy of all files changed since the last full backup. For recovery purposes, only the last full backup and last differential backup is required.
  • Incremental backup – This is an archive copy of all files changed since the last full or incremental backup. For recovery purposes, the last full backup and all the increments since the last backup are required.
  • Primary media – This type of storage is easy to access for quick recovery. A secondary internal hard drive is the common type of media used for primary backups.
  • Secondary media – This type of media is used to store the data originally backed up to the primary media. It is used to provide additional storage on the primary media and allows for a longer recovery time period. External hard drives would be an example of secondary media used today.
  • Primary site – This is generally located somewhere near the machine being backed up. We recommend that while not in use, the backup media is kept in a hidden and secure location since this device has is a direct copy of your system.
  • Secondary site – This location is generally used in case something were to ever happen to the primary site. It is a nearby location that is trusted and secure.

To follow the enterprise model, full backups should be performed in regular intervals with either incremental or differential backups performed between each full backup. An example would be the following:

Sun
Mon
Tue
Wed
Thu
Fri
Sat
Full
Diff
Diff
Full
Diff
Diff
Diff
Full
Diff
Diff
Full
Diff
Diff
Diff

In this case, full backups are performed on Sundays and Wednesdays with differential backups taking place between each full backup. Differential backups where chosen on the basis of ease when needing to restore a file since only the last full backup and the most resent differential backup would be needed to restore the latest version of the file