What is a backup in Commvault
A backup in Commvault is a copy of server data that is stored so it can be used in the event of data loss, errors or system failures. The Commvault Cloud Backup service allows you to protect files and systems by creating secure copies of data and keeping them available over time.
The backup process does more than simply copy data: it follows a set of rules and configurations that determine:
- when backups are performed;
- how long data is retained;
- how different versions of the data are managed.
These aspects are defined through specific configuration elements, such as the
backup plan,
retention and
storage policies.
Backup plan
The backup plan is the central element of data protection in Commvault: it defines the rules for performing and managing server backups. In particular, a backup plan specifies:
- how frequently backups are performed;
- how long data is retained (retention);
- how copies of data are managed over time.
A backup plan is assigned to one or more servers and determines how their data is protected.
The Commvault Cloud Backup service provides preconfigured backup plans that are ready to use. You can use them as they are or adapt them by creating
custom backup plans.
Retention: data retention period
Retention determines how long backed-up data is stored before it is automatically deleted by the system. It therefore defines how far back you can go to recover a file or a previous version of your data. For example:
- with a retention period of 7 days, you can recover data backed up within the last 7 days;
- with a retention period of 30 days, you can recover data backed up within the last 30 days.
When the retention period expires, older versions of the data are automatically deleted to free up space. Retention is one of the most important settings in a backup plan because it directly affects:
- the amount of data you can recover;
- the storage space used by backups;
- the ability to restore data after a certain period of time.
It is therefore important to choose a retention period that meets your needs, considering how long you may need to recover data in the event of an error or data loss.
Backup types
When starting a manual backup, you can choose from different backup types:
- Full - creates a complete copy of all selected data;
- Incremental - backs up only data that has changed since the previous backup;
- Synthetic full - creates a full backup by combining existing backup data without reading it directly from the server again.
If you have no specific requirements, we recommend using an
Incremental backup, as it is faster and has less impact on resources.
Backup sets and subclients
In Commvault, the data to be protected is organized into backup sets and subclients.
A
backup set is a logical container that defines how backup data is organized for a server.
A backup set contains one or more
subclients, which specify exactly which data is included in or excluded from backups.
By default, each server has a
default subclient, which represents the standard configuration of the data to be protected and is used automatically when no specific configuration has been defined.
Managing backup sets allows you, for example, to separate protected data or delete specific sets of backups to free up space.
Storage policy
A
storage policy defines where and how backed-up data is stored. It determines the destination of the data and how copies are managed within the storage system. In the Commvault Cloud Backup service, the storage policy is already configured and managed automatically by the platform, so you do not need to create or modify these settings manually.
The storage policy works together with the backup plan to ensure that data is stored correctly, copies are managed over time and the defined retention rules are followed.
In practice:
- the subclient defines which data is backed up;
- the backup plan defines when backups are performed and how long data is retained;
- the storage policy defines where data is stored.
How the backup process works
The backup process in Commvault is based on the interaction between several elements that work together to protect server data. In simplified terms, the process works as follows:
- the server contains the data to be protected;
- the subclient defines which data is included in the backup;
- the backup plan determines when backups are performed and how long data is retained;
- the storage policy determines where backed-up data is stored.
When a backup is started, either manually or according to a schedule:
- Commvault identifies the data to be backed up based on the subclient;
- performs the backup according to the rules defined in the plan;
- stores the data in the destination specified by the storage policy;
- manages copies over time according to the configured retention period.
All these elements work together automatically, allowing you to protect data without advanced configuration. Understanding the role of each element helps you configure the backup system correctly and understand how it behaves during backup and restore operations.