Back-up

Back-up

1. Requirements

   • Different individuals and organisations have different needs for back-up and recovery which depends on the uses that are made of ICT and the risks to the organisation if data is lost.
     • Loss might occur due to:
       • a hardware default, e.g. a hard disk crash
       • an incident where a file might, e.g. been accidentally deleted or data lost as the result of a natural disaster
       • deliberate actions such as sabotage or terrorism
   • Aim of producing file back-ups is to make sure that if data from a computer is lost or corrupted for any reason, the files can be recovered and the computer system restored to its previous state

2. When planning a back-up procedure the following need to be considered

   • What is to be backed up
     • data files
     • operating system
       • device drivers
       • fonts
       • control panel settings
     • applications
       • after installation are usually customised
   • when is the best time to back up
     • backup can be taken at night
       • for systems that only run during working hours
       • Software can be used that will do this automatically without human intervention
         • Someone must make sure that the back-up tapes are changed every day
     • a backup log should be kept
       • recorded details of all backups taken with details of time, date, the medium used together with the name of the person who carried out the back-up
     • Frequency
       • more frequent the backup the less out of date will be the data when it is restored
       • when a backup is performed, processor time is tied up and files can be unavailable for use
       • balance needs to be found and factors such as time to restore the files in case of failure as well as the importance and nature of data will be taken into account
       • Sale s data for a supermarket, which affects orders and deliveries, will be backed up hourly, if not more frequently.
       • User data, such as names and passwords need only be backed up every week
       • Program files only need to backed up when new versions are installed
   • how the back up should be carried out
   • what media should be used and where the backup media will be kept
   • whose responsibility it is to ensure that backups are taken and that adequate testing of the recovery of backed up data is carried out