Backup & Recovery

Backup & Recovery

1. Individual need for backup and recovery

   • The options for backup and recovery are dependent on:
     • Content & Type
       • What data needs to be backed up?
     • Frequency
       • How often should the backup take place?
     • Timing
       • When is the best time to backup?
     • Backup media
       • What will the data be backed up onto?
     • Location
       • Where will the backup be stored?
     • Responsibility
       • Who will make sure the backup is carried out?
     • Testing & Recovery
       • Make sure that the backup has been successful

2. Backup Media

   • DAT Tapes
     • In most commercial applications the server is backed up using a DAT (Digital Audio Tape) magnetic tape cartridge. This is because they are relatively cheap and so many backup copies can be kept- this helps to ensure that it is possible to go back to older versions of the data if needed.
   • External Hard Drives
     • Small to medium sized business may use an external hard drive for the backing up of data.
   • Internal Hard Drive
     • This is the hard drive which is stored inside the computer. This can be a disadvantage as if the computer is lost or stolen then the backup is gone as well.
   • Online or Remote Backup
     • Online backup services are a popular method of protecting data. The service is normally fully automatic and can take place on a daily basis. This means that the firm doesn't need to allocate any personnel to the task of backing up data. The data is available 24 hours a day and 7 days a week.

3. Location

   • The backup policy will need to indicate where the data backups should be kept. It is always worth considering the worst case scenario when choosing this option, such as:
     • Local Copy of Data: It is essential to keep a backup copy of the data onsite to aid a swift recovery should a user accidentally delete or lose a file. This data would be locked in a fireproof safe for physical security purposes.
     • Off Site Copy of Data: This should be stored on a regular basis and kept off site in case of a natural disaster to the site, or fire or power failure.

4. Content & Backup Type

   • Incremental
     • This method stores all files changed since the last full, differential of incremental backup and it takes the least time to complete. During an incremental backup only the files changed since the lost recent backup are included. Incremental backup provides a faster method of backing up data than repeatedly running full backups, however, it is the slowest method for restoring data.
   • Full
     • This is where all data that needs to be stored is fully backed up each day. If a file needs to be restored it can simply be uploaded from the last full backup taken. However, a full backup takes the most time to store. They are also the quickest method for restoring data.
   • Differential
     • This method stores all files changed since the last full backup and it takes less time to restore data than from an incremental backup. However, restore is slower than a full backup, backing up is slower than than an incremental backup and the storage space requirements are higher than for an incremental backup.

5. Frequency & Timing

   • The backup system will need to be completed at regular intervals, but how frequently depends on how often the data changes. The timing of the backup should depend on when it will have the least impact on the business. Some businesses will need to back up their data as it changes, meaning they will use a continuous backup. For example, in banks as one transaction is processed, the data must be backed up to ensure that no data is lost.

6. Responsibility

   • It is essential that a firm allocates personnel to be in charge of backing up data to ensure that the backup is carried out. In the event of an absence there should be more than one member of staff allocated to the role.