PostgreSQL Storage
PostgreSQL on Thalassa Cloud DBaaS stores database data on Thalassa Cloud block storage. This page covers how primary data volumes work and how to configure storage autoscaling.
For base backups, WAL archiving, retention, and point-in-time recovery, see Backups and recovery.
Block storage
Database volumes use Thalassa Cloud block storage. Volumes are replicated across all availability zones in the region automatically. That applies even when you run a single instance — your data remains durable across AZs at the storage layer.
When you configure multiple instances (instance count > 1), the DBaaS provisions replica instances. Instances are spread across availability zones in the region. If the primary fails, the platform promotes an instance in another AZ. For details, see High availability.
Allocated storage
When you create or update a cluster, you set allocated storage in gigabytes. This is the provisioned size of the database data volume. You are billed for allocated storage; see the pricing page for current tariffs.
You can increase allocated storage later. Plan capacity for growth, indexes, and temporary spikes, or enable storage autoscaling.
Storage autoscaling
Storage autoscaling expands the data volume automatically when usage crosses a threshold you configure. Use it to reduce the risk of write failures from a full disk without manually resizing on every growth event.
| Setting | Description | Default (when enabled) |
|---|---|---|
| Enabled | Turns automatic expansion on or off | Off until you enable it |
| Maximum storage (GB) | Upper bound for provisioned size; required when enabled | — |
| Threshold percent | Usage percentage that triggers an expansion | 90 |
| Increase percent | Percentage of current allocated storage added per expansion | 10 |
| Maximum increase (GB) | Cap on storage added in a single expansion step | 100 |
Behaviour
- The platform monitors used storage relative to allocated storage.
- When usage reaches or exceeds the threshold, it expands allocated storage by the increase percent, subject to the per-step maximum increase.
- Expansion stops when allocated storage would exceed the configured maximum.
Rules to keep in mind:
- Maximum storage must be greater than or equal to current allocated storage.
- Threshold and increase percentages must be between 1 and 100.
- Autoscaling increases capacity; it does not shrink volumes automatically.
- Backups and WAL live in the backup object store, not on the database data volume. Autoscaling does not replace backup retention controls.
When to enable
| Scenario | Guidance |
|---|---|
| Production databases with unpredictable growth | Enable with a clear maximum aligned to budget and compliance |
| Stable, capacity-planned workloads | Manual allocation may be enough; enable if you want a safety margin |
| Development / short-lived clusters | Often leave disabled and size manually |
Summary
| Concern | Where it is managed |
|---|---|
| Database data durability and capacity | This page (block storage + autoscaling) |
| Backup retention, WAL, and restore | Backups and recovery |
| Multi-instance failover | High availability |