CBR Concepts

Vault

CBR stores backups in vaults. Vaults can be either backup vaults or replication vaults.

• Backup vaults store backups of a variety of resources, including servers and disks, and are classified into the following types:
  • Server backup vaults: store backups of non-database servers or database servers. You can associate servers with a server backup vault and apply a backup or replication policy to schedule automatic backups or replications.
  • Disk backup vaults: store only disk backups. You can associate disks with a disk backup vault and apply a backup policy to schedule automatic backups.
  • SFS Turbo backup vaults: store only backups of SFS Turbo file systems. You can associate file systems with an SFS Turbo backup vault and apply a backup policy to schedule automatic backups.
• Replication vaults store only replicas of backups, and such replicas cannot be replicated again. Replication vaults that store replicas of server backups include those for non-database servers and those for database servers.

Backup

A backup is a copy of a particular chunk of data and is usually stored elsewhere so that it may be used to restore the original data in the event of data loss. It can be generated either manually by a one-off backup task or automatically by a periodic backup task.

A one-off backup task is manually created and is executed only once. Periodic backup tasks are automatically executed based on a user-defined backup policy.

• A one-off backup is named manualbk_xxxx and can be user- or system-defined.
• A periodic backup is named autobk_xxxx by CBR.

Backup Policy

A backup policy is a set of rules that define the schedule and retention of backups. After you apply a backup policy to a vault, CBR automatically backs up data and retains backups based on that backup policy.

Replication

Replication is the process of replicating backups from one region to another. You can use the replicas in the destination region to create images and provision servers.

You can manually replicate a single cloud server backup or a hybrid cloud backup. You can also configure replication rules in a policy to periodically replicate backups, including those have not been replicated or failed to be replicated to the destination region.

For example, if you want to back up a server, select Backup for the vault protection type. If you want to replicate backups of this server to a different region, select Replication for the vault in this different region.

Instant Restore

Instant Restore restores data and creates images from backups, much faster than a normal restore.

Instant Restore is an enhanced function of CBR and requires no additional configuration. After Instant Restore is provided, you take less time to restore server data or create images.

Enhanced Backup

Enhanced backups are backups generated after Instant Restore is provided. Enhanced backups make it faster to restore server data or create images.

Before providing Instant Restore, CBR generates common backups. After providing Instant Restore, CBR first performs a full backup for each associated resource and then generates enhanced backups. CBR only generates enhanced backups currently.

For the same resource, an enhanced backup and a common backup have the same backup content and size. They only differ in the restoration speed.

Application-Consistent Backup

There are three types of backups in terms of backup consistency:

• Inconsistent backup: An inconsistent backup contains data taken from different points in time. This typically occurs if changes are made to your files or disks during the backup.
• Crash-consistent backup: A crash-consistent backup captures all data on disks at the time of the backup and does not capture data in memory or any pending I/O operations. Although it cannot ensure application consistency, disks are checked by chkdsk upon operating system restart to restore damaged data and undo logs are used by databases to keep data consistent.
• Application-consistent backup: An application-consistent backup captures data in memory or any pending I/O operations and allows applications to achieve a quiescent and consistent state.

CBR cloud server backup supports both crash-consistent backup and application-consistent backup (also called database server backup). Install the Agent before enabling application-consistent backup to prevent the database server backup from failing.