backup strategy’s :)

Heyy

okay well the blog today is about backup strategy’s Backups are useful mainly for two purposes;

The first is to restore a state following a disaster such as the server blowing up

or

to restore small numbers of files after they have been accidentally deleted or corrupted

a back up strategy is developed by determining which data need to be backed-up and what media to use such as magnetic tape or hard discs can be used. Back ups should be made when no one is likely to being using any of the computers such as in a school a back up should be done around 9pm just making sure that the back up will have finished by the time the school opens. And a backup should always be stored on a secure offsite location

Back up methodology

The most common method of backing up are ;

Full

this methodology transfers a copy of all data within the scope of the back up to the chosen media whether or not the data has been changed since the last back up.

Differential

this backs up all the files changed since the last FULL back up.

incremental

in this case only the files which have changed since the last back up of any kind will be backed up.

Media rotation and storage

a backing up strategy requires media rotation and storage to be considered although most organisations tend to store the back up near the sever which means if there is physical diaster the chance’s are that the back up’s will also be destroyed so it needs to be stored in a secure location offsite which can be retrieved quickly if needed.

Grandfather-Father-Son

If backups are taken each friday on magnetic tape, then daily incremental backups take place from Monday until Thursday, on a Friday , all files will be backed up whether they have been modified or not , the backup runs automatically at a chosen time when the server isnt doing anything else,  on the last working day of each month there is a full back up , after a certain amount of time the tape are re-written with information.   ( i think that is right ?)

The daily backups have the least amount of data, these are son files.
The weekly backups consist of a greater volume of data. These are father files.
The monthly backups contain the oldest data stored and are known as grandfather files.

I hope this right :S

Melissa

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