Secondary storage

Secondary storage

1. Backing storage media

   • Flash drive
     • Moving relatively small files from work to home
     • Smallest
     • Fastest
   • External hard drive
     • Backing up a home computer system
     • Largest
   • CD/DVD/Blu-ray disc
     • Storing multimedia files
   • Magnetic tape
     • Backing up large commercial servers on multiple tapes
     • Second largest
     • Slowest

2. Technologies

   • Optical
     • Laser beams are projected onto a disk
       • Light reflected = data read as 1
       • Light not reflected = data read as 0
     • Used to read and write information to a disk
   • Magnetic
     • Used in floppy disks, hard disks, and tapes
     • Data is stored on a magnetic medium
       • Writing data using a write-head
       • Reading data using a read-head
   • Storage in the cloud
     • Data stored on third-party servers
     • Data replication and backup available
     • Internet connection required

3. Data is written here when it is no longer actively being used, for retrieval at a later date

4. The time taken to access data stored here is longer than accessing data from memory