Guidance on using snapshots for database virtual machines in vCenter Server

Products

VMware vSphere ESXi

Issue/Introduction

Users often ask whether it is recommended to take snapshots of database virtual machines using vCenter Server, and whether such snapshots can be used as a backup mechanism for databases.

While vCenter Server supports quiesced snapshots when VMware Tools is installed, there are important limitations and best-practice considerations when using snapshots for database workloads.

Environment

VMware vCenter 7.x
VMware vCenter 8.x
VMware vCenter 9.x

Cause

VMware virtual machine snapshots are designed to capture the state of a virtual machine at a point in time by creating delta disks. When quiescing is enabled, VMware Tools attempts to coordinate with the guest operating system and applications to flush in-memory data to disk before the snapshot is taken.

For database workloads, this process can introduce the following risks:

Snapshots are not database-aware backups
Snapshot delta disks can grow rapidly for high-I/O database workloads
Long-running snapshots can impact VM and datastore performance
Large snapshots increase the risk of snapshot consolidation failures
Application quiescing may fail or fall back to crash-consistent behavior, depending on the database and workload size

Resolution

VMware does not recommend using virtual machine snapshots as a backup mechanism for databases.

The following guidance applies:

Snapshots are supported only for short-term operational use, such as:
- Prior to operating system patching
- Before application or configuration changes
- Short-term rollback scenarios
Snapshots should be kept for minutes to hours only, and removed as soon as the operation is validated
For database protection and recovery, VMware recommends:
- Native database backup tools (for example, database vendor–provided backup utilities)
- Certified application-aware backup solutions that integrate with VMware APIs for Data Protection (VADP)

Using these methods ensures proper transaction consistency and reduces the risk of data loss or corruption.

Comparison: VM Snapshots vs Database Backup Methods:

The following table summarizes the differences between vCenter virtual machine snapshots and database-aware backup methods for database workloads in vSphere 8.x / 9.x:

Aspect	VM Snapshot (vCenter)	Database-Aware Backup
Purpose	Short-term operational rollback	Data protection and recovery
Transaction consistency	Not guaranteed	Guaranteed
Application awareness	Limited (VMware Tools quiescing)	Fully application-aware
Recommended for production databases	No	Yes
Backup retention	Minutes to hours	Days, weeks, or longer
Performance impact	High for write-intensive workloads	Minimal
Backup growth behavior	Rapid delta growth	Optimized and controlled
Restore granularity	Full VM rollback only	Database or transaction-level restore
Risk of data corruption	Higher if snapshots are long-running	Low when using supported tools
Supported backup strategy	No	Yes
Impact on VCF lifecycle operations	Can negatively impact	Fully supported

Additional Information

VMware snapshots are not backups and should not be used for long-term data retention
Databases with large disk sizes or high write rates are especially susceptible to performance degradation when snapshots are present
Keeping snapshots for extended periods may lead to datastore space exhaustion and VM stun events
Always verify database vendor support and backup recommendations when designing a backup strategy for virtualized databases