© Joseph Mshinga 2024 computer handling
Note.
Hard disks and partitions can either be backed up (imaged) or cloned (duplicated).
Hard disk backup is the processing of copying the entire content of a selected disk to a different disk. Hard Disk
back up is also known as image.
Hard Disk cloning or duplicating a drive
DATA BACKUP CLASSIFICATION.
In general data backups are classified into major types based on:
1. Backup strategy or method (Backup Procedure).
2. Storage media location.
3. How data is copied from source to destination.
TYPES OF DATA BACKUPS BASED ON BACKUP STRATEGIES OR METHODS (BACKUP PROCEDURES).
1. Full backup.
2. Incremental backup.
3. Differential backup.
4. Mirror backup.
FULL BACKUP.
This method creates a copy of all the available files and folders on a regular basis and stores them in a secondary
storage media.
Full backup is done once per week or after every seven days
Advantage.
It takes less time in recovering data, resulting in a faster restoration time.
Disadvantage.
1. It takes longer to backup files as everything is backed up at once.
2. It uses a lot of storage space
3. It consumes a lot of network traffic
4. There is always a risk of data theft if backups are not encrypted.
Use.
Small businesses prefer to use a full backup technique since they usually have fewer data to handle and also this
technique is easier to manage. However, to avoid data theft, backups should be encrypted while employing this
technique.
INCREMENTAL BACKUP.
The incremental backup copies changed files since the last backup of any type, which can be full backup or an
incremental backup.
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© Joseph Mshinga 2024 computer handling
Incremental backup is done every day after the previous full back or incremental backup.
Advantages.
1. Less number of files to be backed up.
2. It takes less space.
3. It takes a very little network bandwidth.
4. It takes a very less time to complete the backup.
Disadvantages.
1. It takes the longest time to restore backups because the last full backup and all subsequent backups must be
applied.
2. A complete restoration of all data may not be possible.
Use.
The incremental backup technique is good for businesses that deal with large amounts of data since it consumes
the least space and allow users to create backups as frequently as they want.
DIFFERENTIAL BACKUP (CUMULATIVE BACKUP).
A differential backup backs up only files that changed since the previous full backup.
This form of backup only requires two backup sets for restoration: an initial full backup and the latest differential
backup, which allows for a faster run and a lesser space requirement.
Advantages.
1. Fast restore because only the last full and the last cumulative backup must be applied.
Disadvantages.
1. More files to be backed up.
2. It takes more time to back up.
3. It requires more storage space.
MIRROR BACKUP.
Mirror data backups are very similar to full backups with the exception that the files are not zip compressed.
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© Joseph Mshinga 2024 computer handling
Mirror backups can also be password protected and be accessed via tools like Windows Explorer.
Advantages.
1. It takes very little time to backup data.
2. It takes very little time to restore data.
Disadvantages.
It uses a lot of storage space.
DIFFERENCE BETWEEN INCREMENTAL AND DIFFERENTIAL BACKUP.
Both of them only back up the added or modified data.
(i). However, incremental backup is created based on any type of the last backup (full backup or incremental
backup). A differential backup is made on the basis of the last full backup.
(ii). Incremental backup takes up less storage space and needs less time during the backup process.
(iii). Incremental backup takes a long time to do a restoration than a differential backup.
(iv). For an incremental backup, a full backup and all incremental backups are required for data restoration. But,
for the differential backup, only full backup and the last differential backup are needed for data restoration.
TYPES OF DATA BACKUPS BASED ON MEDIA STORAGE LOCATION.
OFFSITE DATA BACKUP.
Offsite backup is the copying of data from a production site to a secondary site located at a distance from the
production site.
The two sites are distributed at different location to avoid data loss if a disaster affects the first site. Offsite
storage facilities ensure security with 24 hours surveillance and guards on duty.
ON-SITE DATA BACKUP.
An onsite backup is a system backup of data that is stored locally. This type of backup is typically done on the
business premises.
It is also called Local data backup or Traditional data backup.
CLOUD DATA BACKUP (BACKING UP FILES ON SERVER).
An online backup is when your data is copied to a cloud backup service or storage.
TYPES OF DATA BACKUPS BASED ON THE METHOD TO ACCESS THE STORAGE.
1. Physical data backups/local data backups.
2. Cloud-based data backups/online backups/remote backup.
PHYSICAL DATA BACKUPS (LOCAL DATA BACKUP).
Local data backup is the process of copying the individual data files from one storage device to another storage
devices (storage media).
Access to storage and data
Access to cloud data backup does not use internet connection.
Storing data to local data backup does not use internet connection.
The source devices are disks and the destination devices may include disk, CD-ROM, floppy, Zip drives, and of
course, tape
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