What is computer availability?
The growing dependence on information and the IT systems that store and process it, as well as on professional services provided internally or by third parties, makes it necessary for organisations to implement strategies that ensure that these will be available whenever needed.
What is it?
Within the field of computer and information security, computer availability is the ability to ensure reliability and timely access to data and resources which support the authorised individuals, i.e. they need it to carry out their activities.
How do we achieve availability of information?
The network devices (routers, switches, etc.), IT equipment (servers, disk storage, etc.) and applications must be functioning properly in a predictable and efficient manner, whenever required. In addition, they must recover from disruptions in a secure and timely manner so that productivity is not affected.
To achieve this, organisations define and implement data continuity/availability strategies that ensure that the information and, consequently, the systems that support it, will be available when needed. Some examples of measures to ensure availability are:
- Information backups (data and configuration backups).
- Making disc images.
- RAID system disc set up.
- Use of clustered systems.
- Failover configuration from one system to another.
- Load balancing between computers/systems.
- Redundancy in power and data lines.
- Co-location of installations internally and externally.
Examples of loss of availability
WannaCry attacks (type of Ransonware), suffered by multiple organisations in several countries in 2017, where the information contained on infected computers was encrypted, meant that many companies had to interrupt their activity until the computers were disinfected and the information (data and settings) could be recovered through backups.
Availability is one of the pillars of information security, together with integrity and confidentiality. Its assurance should be a priority for any organisation to avoid productivity losses due to interruptions in the service they provide if the information or the systems that support them are not available.