This topic describes the terms used in Cloud Backup, including backup sources, vaults, backup strategies, and advanced features such as cross-region replication and immutable backup.
Backup source
The data to back up, typically stored on servers, virtual machines (VMs), or Elastic Compute Service (ECS) instances.
Client
The software installed on a source server or VM to back up and restore data. Different backup sources require different clients.
Each client supports timed retry to maintain backup stability. This allows backups to complete even when temporary network jitter occurs.
Region
The physical location of an Alibaba Cloud data center. After a resource is created, its region cannot be changed. For supported regions, see Supported regions.
Data backup
Cloud Backup supports the following backup sources: ECS instances, ECS-hosted databases, Object Storage Service (OSS) objects, File Storage NAS file systems, Tablestore tables, ECS files, on-premises files, and on-premises databases. Backup data is stored in backup vaults on the cloud and can be restored to the original backup source as needed.
Backup vault
A backup vault stores backup data in two tiers: the Standard tier and the Archive tier. Backup data is initially stored in the Standard tier. If automatic archiving is enabled, data is moved to the Archive tier based on the configured archiving policy for long-term, low-cost storage.
To maximize data redundancy, Cloud Backup uses zone-redundant storage (ZRS)-enabled backup vaults by default in regions that support ZRS. In regions that support only locally redundant storage (LRS), Cloud Backup uses LRS-enabled backup vaults. No manual selection is required.
ZRS-enabled backup vaults are available in the following regions: China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Ulanqab), China (Shenzhen), China (Hong Kong), Japan (Tokyo), Singapore, Indonesia (Jakarta), and Germany (Frankfurt).
Vault types
Cloud Backup uses different vault types based on the data source being backed up.
| Vault type | Supported data sources |
|---|---|
| General-purpose backup vault | ECS files, OSS buckets, on-premises NAS file systems, File Storage NAS file systems, large-scale file systems, on-premises files, SAP HANA databases, VMware VMs |
| Database backup vault | MySQL, Oracle, and SQL Server databases |
| OSS backup vault | OSS buckets (30-day free trial). After switching to paid usage, the vault type changes to general-purpose backup vault. |
| NAS backup vault | File Storage NAS file systems (30-day free trial). After switching to paid usage, the vault type changes to general-purpose backup vault. |
| Tablestore backup vault | Tablestore databases |
| Container backup vault | Container Service for Kubernetes (ACK) clusters |
Free trial vault behavior (OSS and NAS)
OSS backup vaults and NAS backup vaults share the same lifecycle rules:
Backup data is retained only for the specified retention period and is automatically deleted afterward.
If you do not switch to paid usage after the 30-day free trial expires, the vault is retained for another 30 days. If you still do not switch to paid usage within those 30 days, the vault is deleted.
Data archiving
Cloud Backup can archive on-premises NAS file systems, Hadoop Distributed File System (HDFS) file systems, and S3-Compatible Storage buckets to archive vaults on the cloud based on specified archiving policies. Cloud Backup provides graphical tools to analyze, search, archive, and retrieve large volumes of data.
Archive vault types
| Vault type | Storage cost | Data access | Restore time | Best for |
|---|---|---|---|---|
| LRS-enabled archive vault | Low | Restore required before access. Charged for retrieval. | About 5 minutes | Long-term archival data, medical images, scientific materials, video footage |
| LRS-enabled cold archive vault | Lowest among all vault types | Restore required before access. Charged for retrieval. | Depends on data size and restoration mode | Ultra-long-term cold data: compliance-mandated retention, big data and AI raw data, film and TV media resources, archived online education videos |
Backup plan
A scheduled or periodic configuration that defines how and when data is backed up. Parameters include the backup source, source path, backup start time, backup interval, and retention period.
Restore job
A task that restores data from a backup vault to the original backup source or a different destination. Parameters include the recovery item, recovery destination, and recovery path.
Backup start time
The time at which Cloud Backup starts a backup.
Backup interval
The frequency at which backups run, such as daily, weekly, or monthly.
Retention period
How long backup data is kept in a backup vault. Backup data is automatically deleted after the retention period expires. The period starts from the time the backup completes.
Backup strategies
Full backup
Backs up all data in a dataset. A full backup reads the entire dataset and stores a complete copy. While this takes longer and requires more storage space, it provides the fastest recovery. Cloud Backup applies deduplication to keep storage consumption under control.
Incremental backup
Backs up only data that has changed since the previous backup, including additions, modifications, and deletions. Incremental backups are faster and more storage-efficient than full backups. However, restoration is slower because the system must trace back through the backup chain to locate the required files.
Incremental-forever backup
Combines the recovery speed of full backups with the efficiency of incremental backups. After the initial full backup, each subsequent backup captures only changed data. Cloud Backup then merges the previous backup copy with the new incremental data into a complete copy, maintaining fast recovery without repeated full backups.
Cloud Backup uses incremental-forever backup for the following scenarios: on-premises file backup, NAS backup, OSS backup, and ECS instance backup (snapshot-based).
Restoration logic
To restore data, Cloud Backup reads data at a specified backup point from the vault, decrypts and decompresses it, and writes it back to the source system.
Advanced features
Automatic archiving
Transfers recovery points from the Standard tier to the Archive tier when backup data needs long-term retention but is rarely accessed. This reduces data protection costs.
For more information, see Automatic archiving.
Cross-account backup
Enables backup and restore across Alibaba Cloud accounts. Enterprises with multiple branches can centrally configure and manage backup jobs. For example, an enterprise can use Account A to back up and restore the data of Account B.
For more information, see Cross-account backup.
Cross-region backup
Creates a remote mirror vault for a backup vault, with data automatically replicated from the source vault to the mirror vault. Cross-region backup is available for the following scenarios: OSS backup, NAS backup, Tablestore backup, on-premises file backup, and VMware VM backup. The mirror vault has the same capacity as the source backup vault. You are charged for the storage capacity and cross-region replication traffic.
For more information, see Cross-region backup.
Mirror vault
A remote repository that stores the same data as a backup vault. Mirror vaults are used to implement cross-region backup.
For more information, see Cross-region backup.
Cross-region replication
Replicates backup data to another region. The approach differs by backup type:
ECS instance backup: Replicate ECS snapshots directly to another region through backup policies. No backup vault is required.
Other backup scenarios: Create a remote mirror vault for a backup vault. Data in the backup vault is automatically replicated to the mirror vault.
For more information, see Cross-region backup.
Special retention period
Retention periods specified in a backup policy for the first backup of each week, month, and year. Special retention periods enable sparse backup, reduce the total number of backup copies, and help meet compliance requirements for data security.
For more information, see Special retention periods.
KMS-based encryption
Encrypts data stored in backup vaults using Key Management Service (KMS)-managed keys. This prevents unauthorized access, data theft, and unauthorized backup or restore operations, helping meet security compliance requirements.
For more information, see KMS-based encryption.
Immutable backup
Protects backup vaults using write once, read many (WORM) technology. After immutable backup is enabled for a vault, data can be written to the vault only once and read multiple times. This feature provides additional protection for your backup vaults. Once enabled, this feature cannot be disabled.
For more information, see Immutable backup.