2. YouWill:
Identify the need to back up.
Explain the different back up procedures available.
Full backup
Differential backup
Incremental backup
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3. Causes of Lost Data
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A company offering backup solutions carried out a survey of
medium to large size businesses who admitted to losing data
in the previous year.The results are shown in the chart.
4. Task
For each of the causes, explain what could have caused the
data loss or corruption and what precautions the companies
could take to try and prevent the loss happening in the
future.
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5. Task
25/11/2015 Safety and Security. Mrs Negri
Create a PowerPoint
about the different
Back Up options that
are available and when
each one should be
used.
8. How Often?
Depends on how often the data is changed and how much the organisation is prepared to
lose.
There is always a possibility of losing data between the time the data becomes corrupted
and the time of the last backup.
Ideal – back up as soon as it changes – most server-based systems have RAID (redundant
array of independent disks) drives – saves the data onto several drives at the same time in
a process called mirroring.
Mirroring – if one drives fails, the next one takes over – no loss of data.
System is essential for data constantly changing and no data loss accepted.
Mission-critical servers the data can be copied to a second server in a different location –
best solution if the computers are in use 24 hours a day – no time for a convenient backup.
Organisations view their management systems critical and see disruption in service as a
disaster.
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9. When?
Most system back up overnight.
Can be an addition to the mirrored drives, sometimes only
backup.
Files cannot be backed up when in use.
Problems?
Program and system files may not change frequently – may
only be backed up when changed.
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10. How?
Full, Incremental and Differential
May need to mix all 3.
Decisions need to be made about how long backup media should be kept before overwritten.
Classic strategy – Grandfather - Father – Son. Less common now as usually undertake daily backups.
Labeled and stored logically – can find and restore easily.
Need to check its been recorded properly and assessable.
Test procedures to make sure organisation can return to normal operations within the scheduled time period.
May involve reserving equipment and office space that could be used to move operations in case of disaster.
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11. Types of Storage Media Used
MagneticTape – Most commonly used medium for storing large
quantities of data. It has high capacity and fairly inexpensive
compared to hard disks. Access is sequential and this makes it
quite a laborious process to find particular files or folders.Time
taken to write or read on a continuous basis can be fast. Can be
faster than hard disks and have remained the main backup
choice for large organisations with large amounts of data.
Hard Disks – become more affordable and now compete with
magnetic tape for the storage of large amount of data. Low
access times, high capacity and easy to use.
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12. Types of Storage Media Used
Optical Disk – 700mb so really only suitable for home or small
organisation. Data can be accessed directly, therefore recovery times
can be slower. Most computers have rewritable CD drives and no
need for expensive extras. Low cost. DVD’s becoming more popular
due to more storage (4.7GB) new technologies like HD-DVD’s and
Blue ray are allowing increased storage space.
Remote Back up Service – high speed internet access means online
backup is becoming more popular. Reduction in the risk of natural
disasters.All data backed up in an offsite location. Needs very high
speed internet access as it will always be slow to back up large
amounts of data from a remote server. Security risks as you trust a
third party.
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13. Responsibilities
Everyone's responsibility to ensure data is backed up.
Network manager takes responsibility for backup based upon the policies that
have been set. Good disaster recovery plan is essential, minimise loss of data.
Specific person needs to be designated to look after backup procedures,
changing tapes and storing them.
Second person if first person is ill.
Continual of service is paramount.
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14. Task
What back up procedures would be best for:
A school.
A company that has lots of data about their customer such as
O2.
A printer company.
Home computer
Include the following: Method, timing, storage, value of data,
where back up will be stored, how accessed in a emergency
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15. Practice Question – ExampleAnswer
One mark for per correct point and one mark for each
expansion/example in context of a home network.
I would recommend that one member of the family puts in
place a regular (1) backup procedure for example at the end
of each day. (1) A suitable medium (1) would be needed for
the backup; for example for a home network, on-line backup
could be used (1) or a recordable DVD. (1)The backups should
be regularly tested to ensure the data from the home
network can be restored. (1) If the backups are not made on
line then their storage location (1) needs to be considered; for
example the designated family member might choose to
store the backups at a friend’s house. (1)
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