1. Objective of this lesson Understand data archives and back-ups

2. Imagine a library There are many different shelves Each shelf contains many books or CDs. Each book/CD is labeled with type and numbers (Eg. Zoology, 0001 to 0029) The library is very organised.

5. It is organised and allows people to access information.

7. A data archive is like a library.

9. A data archive A data archive is like a library Each folder is like a shelf The folder contains many files Each file is like a book on the shelf.

10. Summary of a data archive 1)An archive is very well organised so that people can find information easily. 2)We do not delete older archives because they are never out- dated. The collection keeps growing with new archives. 3)The storage media used for archive must be durable. Eg. Magneto-optical (MO) Disk. 4)An archive contains years of information which people can access. 5)We should protect archives from being modified because the information must be reliable.

11. Archive is a copy of data on durable storage media for long term storage and later access. Definition

12. Video Angels & Demons

13. Then what is a back-up data?

15. A back-up data is an extra copy of data that is important to you. It is to protect ourselves from losing this data. Definition

16. Summary of a back-up 1)A back-up may not be well organised because it is a quick way to protect ourselves even if we lose the original data. 2)We delete older back-ups because they are out-dated. 3)The storage media used for back-up must have high performance speed. Eg. Magnetic tape.

17. Difference between an archive and a back-up?

18. Difference between an archive and a back-up 1)A back-up may not be well organised because it is a quick way to protect ourselves even if we lose the original data. 2)We delete older back- ups because they are out-dated. 3)The storage media used for back-up must have high performance speed. Eg. Magnetic tape. 1)An archive is very well organised so that people can find information easily. 2)We do not delete older archives because they are never out-dated. The collection keeps growing with new archives. 3)The storage media used for archive must be durable. Eg. Magneto-optical (MO) Disk.