Question

In data backup procedures, partial backups are often used. There are two types of daily partial backups: Incremental backup and differential backup.

Use your own words, please explain these two types of backup, and discuss the advantages / disadvantages of each.

Answer 1

Incremental backup

these are the backups which consider the data from last backup whether full backup or partial backup.

Example - suppose you take a full backup on Sunday . On tuesday you take the incremental backup, this will cover backup from Sunday to Tuesday. Now again you take a backup on Friday , this will take the backup from Tuesday to Friday.

Advantage-

1. No data duplication.

2. Data backup is faster than full or differential backup.

3. Since , only a small amount is backed up , needs very less space.

4. Time taken is very less.

Disadvantage

1. Recovery is slower bcoz of several backups.

2. Initial full backup is needed for subsequent incremental backups.

3.if one of the backup fails , whole process will be incomplete.

Differential backup

in these backups , every time backup is taken from last full backup .

If we take differential backup instead of incremental , in our last backup , the only difference will be that on Friday again we will take backup from Sunday to Friday (not from Tuesday)

Advantage

1. Faster than full backup.

2. Even if one of the backup fails , full recovery is possible.

3. Less storage space needed

Disadvantage

1. Slower backup than incremental

2.restoring is slower than full backup

3. More storage space than full backup