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Incremental backup is a feature that analyses your files, finds new and modified files and uploads only those files to your storage. To perform the incremental backup you need, of course, to perform an initial full backup. (Needless to say, this is one of the most efficient ways to perform your backup.


What Is Incremental Backup

As we have already mentioned, incremental backup only uploads new or modified files. Let’s see how it works.

Imagine that you have five files for backup and you are going to run weekly backup.

The first-week backup (initial full backup) will include all of them.

The second week, file1, file3 and file4 have been modified.

The second-week backup will only copy your modified files: file1m, file3m, file4m.

The following week, file2 and file5 have been modified. They become file2m and file5m.

The third-week backup will only copy your modified files file2m and file5m.

In the end, you have a dataset with several files completely changed. Each week, only the modified files were uploaded.

That is how incremental backup essentially works. And if a file is not changed but added to the backup set after week 3, it will appear in week 4 as file6.


The Advantages of Incremental Backup


There are specific advantages to performing incremental backups compared to full backups. They are:

Faster backups. Incremental backup will upload only changed and new files in the cloud or local storage. This is considerably faster than uploading an entire dataset each time.

Less storage capacity needed. Storage space means money. The less storage space you need, the less you will pay to your cloud storage provider. If you perform local backup, you will spend less on your hard drives.

Less bandwidth is consumed. When you perform a backup, the last thing you want is for it to cause your Internet connection to hang.


The Disadvantages of Incremental Backup


  • Perform full backups from time to time. When you perform a full backup, you break the sequence of the previous incremental backups. In other words, you will backup only the files that currently exist on your device; the incremental backup only adds new files and changes since that last full backup.


  • Set a retention policy for your files. A retention policy allows you to choose how long you keep your old files and how many versions of each file you keep. With incremental backup, it’s recommended to set a policy that allows you to delete old files after a given time, or files that have been deleted from your device. A retention policy is a flexible tool. See the tab for this in the help section.


Incremental Backup Software


Backup Monkey fully supports the concept of incremental backup, both locally and to the cloud, and enhances it with additional features. Our software performs incremental backup by default to ensure that there are no unnecessary copies of files and your storage space is used wisely.

However, depending on your needs, an incremental backup may not be enough — and you may want to look at an option called block-level incremental backup.

Block-Level Incremental Backup


Block-level backup performs in-depth file analysis and backs up only the modified portions of files, which makes it  an efficient tool when used properly.

This functionality is featured in Backup Monkey and can be easily toggled from the UI of the software by going to the Backup Plan Wizard, then Advanced Settings.

Point-in-Time Recovery from Incremental Backup


If you use incremental backup and have configured your backup plan well, then you will be able to recover your data, when needed, to the chosen point in time.

As an example, let’s say that your computer has been hit with ransomware. Luckily, your backup software has uploaded all your files to the cloud, and you can simply recover your files to the state of the previous week or point in time when your files were not affected by ransomware.



What Is Block-Level Backup?

Block-level backup is a type of backup that allows you to back up only modified parts of the files instead of running a full backup every time the file is changed. Block-level backup takes less bandwidth for regular backups and reduces the backup time.

How to Use Block-Level Backup Software?

Open Backup Monkey Wizard and select the Use block level backup checkbox on the Advanced Options step.

When you first run backup plan with the block-level backup feature enabled, full copy of each file will be uploaded to storage. Next time you run a backup plan, only modified parts of the previously uploaded files will be moved to storage. All the new files will be also backed up.

Note: If you choose to use block-level backup, you will see the Full Backup Schedule screen where you can specify conditions for performing a Full Backup. Full Backup is only related to block-level backup and is a part of it. Full Backup affects only individual files, not the whole backup set.

Initial Backup and Blocks

Every time a block-level backup is performed, Backup Monkey checks whether your files were modified. If they were, backup client will identify modified blocks and move them to storage.

Full copy is kept in a storage as it was uploaded and all the blocks containing modifications is applied to that copy. It is recommended to run full backup from time to time.

Note: Modified blocks of the originally backed up file require additional storage space.

Purge and Block-Level Backup

Backup Monkey Wizard allows you to setup purge options. You can set up an expiration period for each version of file and specify number of versions to keep on storage. These purge options can be used mutually.

Block-level backup creates modified blocks – “diffs” related to a full copy of a file, without the full copy diffs won’t be of any use. That is a reason why Purge feature takes effect only when you have two or more full copies – if you have just one full copy of a file purge won’t work. Any full or diff is considered as a version. However, a diff can’t be purged if the related full still exists and also full can’t be purged if there are diffs related to it.

Imagine that you’ve made a full backup of a file and set Backup Monkey to keep 3 latest versions:

Versions Comments
F1 – full copy #1 Now you have just one full copy.
D1.1 – diff 1.1 Now you have full copy and one set of modified blocks – D1.1.
D1.2 – diff 1.2 You have F1, D1.1 and D1.2.
D1.3 – diff 1.3 Now you have four versions and may expect that your F1 will be purged but it will not be purged because there are diffs assigned to it.
F2 – full copy #2 You decide to make a full backup and now have five versions. You may be expecting F1 and D1 to be purged but they will not be purged because there are D1.2 and D1.3 assigned to F1. D1.2 and D1.3 are in number of 3 latest versions so all the related data can not be deleted.
D2.1 – diff 2.1 Now you have six versions and may be expecting F1, D1.1 and D1.2 to be purged but they will not be purged because D1.3 links to F1. And D1.3 is in number of 3 latest versions.
D2.2 – diff 2.2 F1 and D1.1 and D1.2 and D1.3 will be purged. Now you have three versions.

See the image below for better understanding:

How to Setup Full Backup According to a Percentage of File Modifications

On the Full Backup Schedule screen you can set up a conditions to run full backup. Just check the “Run full only if total size of previous level backups larger than:” checkbox. You will have to specify a percentage of total changes from last full size of a file. When total changes in a file will reach the threshold, a full backup will be initiated.


Any backup application has the following essential feature — a possibility to delete unnecessary copies automatically and thus save cloud storage space. This feature is called Retention Policy in Backup Monkey. This article provides detailed information about the logic of this policy operation and its useful peculiarities.

Versions History

To clean the storage space and delete all outdated backup copies it is very convenient to work with them in the version history format. It means that all user files are accompanied by a list of their previous versions in the backup system. In this case it is easy to link the entire scheme to corporate policies and make the cleaning process automatic.

All options of Retention Policy are available in the backup plan settings you choose. To get a clear understanding of it, choose any backup plan, click Edit Backup Plan and set Advanced Backup Mode. All settings of Retention Policy are available at the same-name step.


Delete Versions Older Than

This parameter deletes all file versions that were created before a certain date (day, week, month and year can be chosen) as measured against the initial backup or last modification date of your files.

In addition, you can check the box Always keep the last version that acts as a kind of a safety lock and prevents last version loss even if it is out of date according to the policy settings.

Keep Number of Versions

You can refrain from specifying the date and just store, let’s say, three last versions of the file. It is convenient for data that are rarely updated. For example, information on the website is rarely updated but it would be a good idea to have any history in case of its loss or a suddenly detected bug. Just choose Keep number of versions and set the required number of copies.

There’s also a useful check box called Delay purge for. It can be another one safety lock for your backup strategy. It just delays the cleaning process scheduled by the system for a certain period of time being a kind of an analog of pop-up button “cancel” that appears when we send e-mails via Google services.

Delete Files That Have Been Deleted Locally

It is one of the most useful options, in our opinion. First of all, it will become popular among companies having large volumes of data required to be stored for a long time. For example, if you need to store virtual machine files for 1+ year (yes, sometimes such things happen). But sometimes it so happens that a few machines are replaced by new ones and “earlier” versions survive their usefulness.

Generally, it presupposes storage of a few dozen GB of useless data in a cloud for a year. Use Delete files that have been deleted locally if you don’t want to remember such situations. In this case when data are deleted from the server, they will be automatically deleted from the cloud. This option is also recommended to be used with the above mentioned parameter Delay purge for. Just in case.

By the way, all these parameters in our case are related to a certain plan. If you choose Use default on the Retention Policy tab, global options (Tools – Options – Retention Policy) will be applied. This variant is convenient in case of using typical parameters for most backup plans.

Block Mode and Retention Policy

The following question is frequently asked: “I set storage of 3 versions but now I have 5 versions and nothing is deleted. Why?”

The peculiarity of block backup operation with increment versions is in the fact that all versions comprise a single chain. Consequently, it is broken when some links are deleted and part of information in the backup version becomes damaged. Of course, Backup Monkey will not do it with your data.

In order to avoid this situation with the Retention Policy, you just have to generate a new chain of versions in due time. You can do it automatically by means of Full Backup Schedule options of the backup plan:

Schedule full backup with following settings — if you check this box, you will see an additional window with the timetable where you can choose certain periods of full backup copy creation;


Run full only if total size of previous block level backups larger than — here you can set a percentage ratio that cannot be exceeded by increment copies in relation to the full version. If their size exceeds the limit, a new full copy containing its own chain of backup copies is created. And all other copies of the earlier chain can be deleted without any consequences.


Note: this “full” backup will include only new and modified files (i.e. it will be an incremental backup). It won’t back up all unchanged file versions over again – it allows to save your storage space and costs. At the same time you can be sure that all your files are up to date on the cloud storage. No need to upload all the files selected for backup – you will have duplicated data on your cloud storage.


All data transferred to your cloud storage solution is free.

Data transfer from the cloud is chargeable. The first 1TB/500GB per licence, per year, is free, after that there is a per TB charge (contact your provider for this information).


Licences include the following amount of free cloud storage per year:
Desktop – 500GB
All Servers – 1TB
VM Hosts – 1TB for every 2 cpu slots

Any server/licence using over the limit will incur extra charges, however storage can be pooled across machines (e.g. 3 licences = 3TB of storage over 3 machines). Please consult your solution provider for further information.