1. AS ICT Module 2 Objectives: 11.8 - Security of Data
Backup Systems: understand the need for regular and systematic backup and procedures for recovery.

2. Remember the REASONS for backing-up data
Security of Data
Threats to
Computer Systems
Data Integrity
Input errors
Operating procedure errors
Program errors and file corruption
Disaster Planning
Fraudulent use
Malicious damage
Viruses
Security measures
Remember the REASONS for backing-up data

3. Archiving and Backup 11.8 - Security of Data
The copying of data from one place to another, leaving the original intact.
This is a file attribute which can be "set" or "cleared". If set it tells you that the file has been created or modified since the last backup. When a backup is taken using a backing up program, this attribute is cleared.

4. TYPES OF BACKUP 11.8 - Security of Data
NORMAL – copies all selected files to the backup medium and clears the ARCHIVE attribute for each file.
INCREMENTAL – copies only the files that have changed since the most recent backup and clears the ARCHIVE attribute.
DIFFERENTIAL – copies files that have changed since the last backup, but does not clear the ARCHIVE attribute. Successive differential backups therefore copy all of the files that have changed since the last normal or incremental backup.
TYPES OF BACKUP
COPY – copies but does not clear the ARCHIVE attribute. This means a copy of a file can be made without affecting the normal backup routine.
DAILY– copies but does not clear the ARCHIVE attribute for the files that have changed on that day.

5. Backup Considerations
Security of Data
Backup Considerations
FREQUENCY – how often should you backup?
MEDIUM – what should you backup onto?
LOCATION – where should you store backups? Is there a secure location?
NUMBER OF GENERATIONS – how many and for how long?
RESPONSIBILITY – who is responsible for the backup and the backup strategy?
TESTING OF RECOVERY PROCEDURES – when will this be carried out? Who will do it?

6. What to Backup Programs? Data? NO YES 11.8 - Security of Data
There is no need to back up programs – these can be restored by their installation disks. Backups are easier without having to backup the software too.
YES
This data is created by software after installation and is stored independently. It must be backed-up as it is not on the original installation disk.

7. Backup Media Floppy Disks Zip Disks Online CD-ROM / CD-R / CD-RW
Security of Data
Backup Media
What to backup on
Floppy Disks
Zip Disks
CD-ROM / CD-R / CD-RW
DVD-ROM / DVD-RW
Online
RAID
Tape
Peer To Peer
Pen Drive

8. Copies 1 and 3 are still safe
Security of Data
What is RAID?
RAID stands for Redundant Array of Inexpensive Disks
DATABASE SYSTEM
Performs daily backups. Many copies are made to different disks.
BACKUP FAILURE
COPY 1
Same room
COPY 2
Online
COPY 3
Offsite
Copies 1 and 3 are still safe