Storage types and devices

Storage types and devices

1. what is backing up of data?

   • copying files in case of a problem with the secondary storage device.

2. Why back up data?

   • safeguard against data loss
   • safeguard against damage caused by hackers
   • need to be used elsewhere to protect against corruption
   • does not protect against viruses
   • advantages
   • disadvantages

3. Types of access

   • serial access
     • mainly used on magnetic tape systems
   • field
   • record
   • file
   • direct access
     • used on magnetic disk, optical media and solid state media
     • uses key to figure out where data should be stored
     • directly access data from a calculated position. Much faster than serial access

4. Magnetic storage media

   • Fixed internal hard disk drive
     • used to store the operating system, systems software and working data/ files. It can also be used for storing application software for fast retrieval and storage of data. used in real time systems such as robots, control of chemical plant. it is also used for online system such as booking airline tickets or automatic stocks. used in file severs for computer networks
     • advantages
     • disadvantages
     • very fast data transfer rate and fast access time to data
     • very large memory capacity
     • can be easily damaged if not shut down correct
     • many moving parts when compared to a solid state drive
   • Portable hard disk drive
   • Magnetic tapes

Images and files in the map