Technical guide on creating and managing VPS snapshots in SolusVM 2. Learn how to take point-in-time backups before major upgrades and perform instant rollbacks to prevent data loss.
Creating and Managing Point-in-Time VPS Snapshots
A Snapshot is a block-level capture of your Virtual Private Server's state at a specific moment in time. Unlike traditional file-based backups, a snapshot includes the entire disk state, including the filesystem and configuration. At Hovixa, snapshots are the primary tool for "safety-net" administration—allowing you to revert your entire server to a previous state in seconds if a software update or configuration change fails.
1. The Difference Between Snapshots and Backups
It is analytically important to distinguish these two technologies to avoid data loss during a disaster recovery scenario:
| Feature | Snapshot | Standard Backup |
|---|---|---|
| Speed | Near-instant creation and rollback. | Slower (requires file transfer). |
| Storage | Stored on the same NVMe node. | Stored on independent backup servers. |
| Retention | Temporary (pre-update/testing). | Long-term (disaster recovery). |
| Dependency | Dependent on the parent disk. | Self-contained. |
2. Creating a Snapshot
Before performing a major operation (e.g., upgrading from Ubuntu 22.04 to 24.04 or modifying a production database schema), follow these steps:
- Log in to vm.hovixa.com.
- Select your VM and navigate to the Snapshots tab.
- (Optional but Recommended) Perform an ACPI Shutdown on your VM. While SolusVM 2 supports "live" snapshots, a powered-off snapshot ensures absolute data consistency (filesystem quiescence).
- Enter a descriptive name (e.g.,
Pre-Nginx-Config-Change). - Click Create Snapshot.
3. Rolling Back to a Previous State
If your changes cause a system failure, you can roll back the entire disk image to the snapshot state.
- Go to the Snapshots tab.
- Identify the relevant snapshot in the list.
- Click the Restore (clock icon) button.
- Confirm the restore. Warning: Any data written to the disk *after* the snapshot was taken will be permanently overwritten.
- The VM will reboot using the disk state from the moment the snapshot was captured.
4. Managing and Deleting Snapshots
Because snapshots are stored on the high-performance NVMe drives alongside your active data, they consume resources. Most Hovixa plans allow for one or two concurrent snapshots.
- Consolidation: Once you have verified that your server changes are successful and stable, you should Delete the snapshot to free up space and optimize disk I/O.
- Automated Purge: Snapshots are not meant for permanent storage. Leaving snapshots active for weeks can lead to performance degradation of the virtual disk.
5. Technical Implementation Details
- Copy-on-Write (CoW): Hovixa uses QCOW2 snapshots. When you take a snapshot, the system begins writing new data to a delta file. Restoring the snapshot simply involves discarding that delta.
- RAM State: Snapshots at Hovixa capture the Disk State only. They do not save the contents of the volatile RAM. When you restore a snapshot, the VM will undergo a fresh boot sequence.
- Database Integrity: If you take a snapshot while a heavy database write is occurring, there is a small risk of "crash-consistency" issues. Always stop high-traffic services before snapshotting for 100% reliability.
Sysadmin Advice: Never use a snapshot as your only backup strategy. If the physical hardware node fails, both the VM and the snapshot are lost. Use snapshots for administrative safety and external backups for data insurance.
