What is the difference between differential incremental and differential backups?

Differences between full, incremental, and differential backups:

A full backup backs up all data, while incremental backups and differential backups only back up changed data.

Compared with incremental and differential backups, full backups have less time, higher efficiency, and occupy less disk space.

Difference between differential and incremental backups:

1) Differential backup only backs up the changed data on the basis of a full backup; Incremental backup: The previous backup is the basic backup, and the data is changed.

2) Differential backup only has a dependency relationship with a full backup, not with the previous backup; Incremental backups have dependencies on the previous backup and remain relevant to full backups.

This section describes the types of backups and how to combine them.

Full Backup Backs up all selected folders and does not depend on the archive properties of the files to determine which files to back up.

During the backup process, any existing tags are cleared, and each file is marked as backed up, in other words, the archive properties are cleared).

During a differential backup, only those selected files and folders that are marked are backed up. It does not clear the markup, i.e., the file is not marked as backed up after backup, in other words, it does not clear the archive attributes).

During an incremental backup, only the selected files and folders that are marked are backed up, and it clears the markers, i.e., the files are marked after the backup, in other words, the archive properties are cleared. ）

An example of a combination of different backup types.

Full and differential backups.

Full backups are taken on Monday and differential backups are taken from Tuesday to Friday. If the data is corrupted on Friday, you only need to restore the full backup on Monday and the differential backup on Thursday. This strategy takes more time to back up your data, but less time to restore your data.

Full and incremental backups.

Full backups are taken on Mondays and incremental backups are taken from Tuesday to Friday. If the data is corrupted on Friday, you need to restore the normal backup on Monday and all incremental backups from Tuesday to Friday. This strategy takes more time to back up your data, but less time to restore your data.

What are the advantages of differential backups? （）

a.The time is short.

b.Requires less tape.

c.Short recovery time.

d.Long recovery time.

3. One of the tasks of the system management of true/false questions is to be able to protect, backup, restore and update the security of programs and data in a slippery and distributed environment. (a) A: True B: False.

Correct answer: ABC

Incremental backup records changes for each time on the basis of the first full backup. Because incremental backups determine whether the data has changed before backup, and only record each change.

Differential backup records the difference between the latest data and the first full backup on the basis of the first full backup. To put it simply, differential backup is a process of accumulating changes: after a full backup, the changes of the first day are recorded on the first day, the changes of the first day and the second day are recorded on the second day, and so on.

In contrast, incremental backups have the greatest benefit in that they require the least amount of storage space (for the same change), have the fastest backups, and have the longest data recovery time. On the other hand, the data recovery time of differential backups is relatively short, and the storage space required for backups is larger than that of incremental backups.

Therefore, the choice of backup method should be based on the actual needs of backup storage space, backup speed, recovery time, etc.

1. Differences in meaning.

An incremental backup is a full backup or the last incremental backup, and each subsequent backup only needs to back up the files that have been added or modified compared with the previous one.

A differential backup is a backup that copies all data that has changed since the last full backup.

2. Differences in characteristics.

Incremental backup has no duplicate backup data, the amount of data backed up is not large, the time required for backup is very short, and the backup speed is fast. At the same time, since incremental backup will automatically determine whether the backup time and files have been changed before making a backup, it is also beneficial to save storage space compared to full backup.

Differential backups require short, disk-space-saving advantages; Backup and recovery require less tape and have short recovery times. The system administrator only needs two tapes, the full backup tape and the difference backup tape the day before the disaster, to restore the system.

Full Backup: Back up all the data in your system.

Differential backup: Only the data that has changed since the last full backup is backed up (the last full backup is targeted, and the archive attributes are not cleared during the backup process).

Incremental backup: Only data that has changed since the last backup is backed up. (He doesn't care what type of backup, if there is a change in the data, he will back it up, and he will clear the archive attributes).

Restore speed from slow to fast: incremental backup, differential backup, full backup.

Poor old sales difference backup refers to ().

a.It refers to the backup of files that are added or modified during the virtual travel time between a full dusty backup and a differential backup.

b.The data backed up each time is only equivalent to the data that has been added and modified since the last backup.

c.Back up one copy of all your data at a time.

d.There are differences between each backup and the previous one.

Correct Answer: a