Vinchin Blog Understanding VM Backup Types: Full vs Differential vs Incremental vs Forever-Incremental Backup

Understanding VM Backup Types: Full vs Differential vs Incremental vs Forever-Incremental Backup

2022-11-02 | Echo

Table of contents
  • Full Backup
  • Incremental Backup
  • Forever-Incremental Backup
  • Differential Backup
  • Full vs Incremental vs Forever-Incremental vs Differential
  • Which backup type to use?
  • The ideal backup solution for your answers
  • Summary


Creating backups of collected business data is incredibly important for organization data management, which saves time and cost in the event of ransomware attacks, hardware malfunctions, system failure, site outages, and natural disasters.

In general, there are 3 VM backup types: full, differential, incremental, and the newly emerged forever incremental backup. Understanding their differences plays a significant part in forming a suitable backup strategy for every business. Below is the introduction and comparison of 4 backup types, so you can tailor your backup needs.

Full Backup

A full backup makes a complete copy of the whole data set including files, folders, hard drives, etc. Basically, all the data is transmitted to a storage device in a single operation. Given its data integrity, a full backup is the basis of all the other backup types, and the best data loss prevention method for organizations. However, the time, network, and storage it consumes are also considerable.

A full backup includes old files, changes made in the old files, and new files data during the process, below is the schematic diagram of a full backup:

流程图_画板 1.jpg


  • Recover all the lost data without missing any files.

  • Take the shortest time for data recovery.

  • Easy to manage storage.

  • Simple access to data.


  • Eat up huge storage space due to the large data volume.

  • Consume longer backup time than others.

  • Occupy network workload when it runs.

  • May interfere with normal operations during the process.

  • High data loss risk considering that all data is kept in one location.

Incremental Backup

Incremental backup reduces the network bandwidth and storage space needed to run a series of full backups and complements them for an optimal VM backup. First, make a full backup as the incremental base, then back up only the modified data since the last backup. The backup retention setting decides the full backup cycle within a specific amount of time. 

But the full recovery spends a long time because it needs the last full backup and all the following incremental backups until the restoration point. So, an absent increment in the chain will upset the recovery.

Here is a diagram showing how an incremental backup works:

流程图_画板 1 副本.jpg


  • Faster than the full backup since it only backs up increments.

  • Need less storage space and bandwidth than the full backup.

  • Complement the full backup and run as needed.

  • Each incremental backup can be a flexible recovery point.


  • Full recovery is slower.

  • The complete increment chain is essential for data recovery.

  • May experience system downtime because of an incomplete data chain.

Forever-Incremental Backup

As a branch of incremental backup, forever-incremental backup only copies increments after an initial full backup but it won’t make regular full backups as the former does. The backup retention policy determines the “data expiry” in which the outdated backup data and recovery points will be deleted to release storage space.

The backup processes are completed quickly and the repository uses the least amount of space because only the modified data is copied. But it needs to reconstruct recovery resources from the full backup and subsequent increments to the recovery point.

The process is shown schematically in the following figure:



  • Backup and recovery are fast.

  • Enhanced storage management.

  • Minimal storage space consumption.

  • Take less network bandwidth.


  • Reconstruct data for recovery.

Differential Backup

Differential backup saves only the difference in the data since the last full backup. Since changes to data are relatively fewer than the entire dataset, the backup and recovery time are shorter than full and incremental backup respectively because it only entails the initial full backup and latest differential backup for recovery, which simplifies data restoration as well.

The below picture showcases its working procedures:

流程图_画板 1 副本 2.jpg


  • Much faster backup than a full backup.

  • Faster recovery than an incremental backup.

  • Occupy less storage than a full backup.


  • Slower backup and need more storage than an incremental backup.

  • Slower recovery than a full backup.

Full vs Incremental vs Forever-Incremental vs Differential

Backup Type   

Full backup
Incremental backup   Forever-incremental backup                     Differential backup 

Backup Content      

All data Initial full backup + changes since the last backup                 Initial full backup + changes since the last backup   Initial full backup + changes since the last full backup

Storage Consumption

Large                   Small  The smallest                   Medium

Network Bandwidth 

HighLow   Low   Medium

Backup Speed

SlowThe fastest                    The fastest                    Fast    

Recovery Speed  

The fastest Slow   Slow   Fast    

Restore to Full Backup

Requires the last backup   Requires the last full backup + incremental backups until the recovery pointsRequires the last full backup + incremental backups until the recovery pointsRequires the last full backup + differential backups

Use Case  

When a backup small amount of data or any other backup typesWhen backup large data volumes in a large environmentWhen backup large data volumes in a large environment    When processing large amounts of data but are unable to perform constant backups

Which backup type to use?

Choosing which backup type or combination hinges on multiple factors.

Data amount: How much data are you backing up and restoring?

RTO (recovery time objective): How long will you need to restore lost data in the event of a disaster?

RPO (recovery point objective): How much data will you tolerate losing in the data loss incidents?

Backup locations: Where do you place your data, onsite, offsite, or on the cloud?

Backup storage type: Tape, SSD, cloud, external drives, or hybrid?

IT environment: What software applications and operating system(s) does your company employ? Bandwidth, server location, storage space, and other aspects of the infrastructure.

The ideal backup solution for your answers

After you have decided on your backup types, you are good to back up. A solid backup partner with various backup techniques plus BCDR (business continuity and disaster recovery) strategies is a great choice.

Vinchin Backup & Recovery is a robust backup solution that integrates easy backup, V2V migration, and fast recovery for 10+ platforms, including VMware, Hyper-V, oVirt, XenServer, OpenStack, etc., 6 databasesLinux & Windows Servers, and NAS.

vinchin computer.png

Multiple backup choices: Make your decisions from full, differential, and CBT-enabled forever incremental backup and keep data with GFS mode.

Less storage consumption: Deduplicate and compress data to minimize storage consumption.

Automatic backup: Automate backup with backup schedules and email notifications through encrypted, multithreaded, and other specialized transmission modes.

Anti-ransomware data protection: Protect data against surrounding threats with data backup storage, offsite backup copy, data archiving to public clouds, and data encryption.

Cross-platform V2V migration: Convert easily a source virtualization to the target platform within 4 steps.

15s Instant recovery: Retrieve corrupted VM from local backups or offsite backup copies in 15s for shorter RTO.

Besides that, Vinchin Backup & Recovery also supports database protection for Oracle Database, MySQL, SQL Server, PostgreSQL, Postgres Pro, and MariaDB. To back up and protect your critical data scientifically and comprehensively, you are welcome to download the 60-day free trial below.


Backup type isn’t generally good or bad, it’s all about how you use it or mix them based on individual business needs dictated by your data protection strategies, accessible media resources, bandwidth, etc. However, forever-incremental backup does significantly improve the data backup and therefore meets companies’ needs as cutting-edge technology.

Vinchin Backup & Recovery uses CBT/SpeedKit (CBT alternative) forever-incremental backup and other backup combinations to take speedy and frequent backups for the handy data recovery of organizations.

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Categories: Technical
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