Backup Methods

Backup Methods

1. Incremental

   • A full backup of entire hard disk made once a week for example every Monday. On other days, only those files that have been changed during that day are backed up. It is less time consuming however it is more complex to restore as all backups have to be restored in the correct sequence.

2. Remote

   • The backup software switches itself on automatically for example at 12 am when all users have logged off the network. It makes use of the computer facilities that are otherwise idle, and can proceed unsupervised.

3. Raid

   • Redundant Array of Inexpensive Disks (RAID) enables data to be written simultaneously to several disks. 3 copies of a database may be held, 2 locally and 1 on a remote system. If 1 system fails, data can still be used on either of the other 2.

4. Grandfather-Father-Son

   • Everyday of the week is backed up, and they are known as the 'Sons'. At the end of the week, there are seven 'Sons'. The oldest 'Son' will be put aside at the end of the week and is now known as the 'Father'. This will happen for every week in a month, so there is 4 'Fathers' at the end of the month. The oldest one again is put aside and is now known as the 'Grandfather'. Each year 12 'Grandfather' backups are stored.

5. Full

   • Copy of all files on fixed disks. It is very safe and simple to restore. However, it is time-consuming and computers can't be used while making back-up.