Volumes
UNIQCloud Block Storage Overview
UNIQCloud offers two distinct types of block storage to meet your data persistence and performance needs: ephemeral storage and persistent volumes.
Ephemeral Storage
Avoid using for production workloads unless you fully understand the potential risks and implications.
Ephemeral storage is directly tied to the lifecycle of a virtual machine instance. It remains available through guest operating system reboots but is permanently deleted when the instance itself is terminated. The capacity of ephemeral storage is determined by the instance's flavor and remains consistent across all instances of that flavor. Performance characteristics are influenced by the underlying hardware infrastructure.
Persistent Volumes
Persistent volumes are virtualized block storage devices designed for durability and flexibility. Unlike ephemeral storage, these volumes exist independently of any specific instance. You can attach a persistent volume to a single instance at a time—similar to connecting a USB drive—detach it, and reattach it to another instance without losing data. Persistent volumes leverage CEPH for redundancy, ensuring high resilience against hardware failures.
Key Features:
- Flexibility: Attach additional volumes to an instance beyond the default system disk.
- Scalability: Expand storage capacity beyond the limits of your instance's flavor.
- Mobility: Easily move volumes between instances or create snapshots for backup and recovery.
Volume Types
UNIQCloud provides three classes of Cinder volumes, each optimized for different Input/Output Operations Per Second (IOPS) requirements. These volumes are available across all local zones.
| Volume Type | IOPS | Description | Replication |
|---|---|---|---|
| iops3 | 4000 | High-performance volume, ideal for workloads requiring rapid data access. | Replicated across all local availability zones |
| iops2 | 1000 | Balanced performance, suitable for general-purpose applications. | Replicated across all local availability zones |
| iops1 | 500 | Cost-effective option for low-intensity or archival workloads. | Replicated across all local availability zones |