# Storage

We offer reliable and resilient storage volumes that supports high I/O operations, with flexible expansion capability that grows with your storage needs.

<table><thead><tr><th width="182">Storage Type</th><th width="271">Disk Type</th><th width="284">Disk Size</th></tr></thead><tbody><tr><td>Boot Disk</td><td>Basic/Standard NVMe SSD</td><td>20 GB to 2048 GB</td></tr><tr><td>Disk</td><td>Basic/Standard NVMe SSD</td><td>20 GB to 32768 GB</td></tr></tbody></table>

{% hint style="info" %} <mark style="color:blue;">**Note**</mark>

* <mark style="color:blue;">Boot Disk cannot be detached and can only be deleted along with its instance.</mark>
* <mark style="color:blue;">Disk created along with the instance can be detached. You can also create additional detachable disks afterward separately on Disk page.</mark>
  {% endhint %}

## Boot Disk

Boot disk is used to store your operating system. The disk size cannot be smaller than that of your operating system.

## Disk

Cost-effective disks are provided to give your instance more elastic storage space with highly available block storage.

### Overview

The virtualization platform provides two types of cloud disks:

* **Basic NVMe SSD**
* **Standard NVMe SSD**

Both disk types are designed with triple-replica (3-replica) architecture to ensure high data availability and reliability. While they share the same redundancy mechanism and throughput scaling model, they differ in performance characteristics, particularly in IOPS scaling and burst capability.

### Data Reliability

All cloud disks use a three-replica mechanism, meaning each piece of data is stored in three separate locations. This design ensures:

* High availability
* Fault tolerance against hardware failures
* Strong data durability

### Performance Characteristics

#### 1. IOPS (Input/Output Operations Per Second)

| Disk Type         | Base IOPS | IOPS per GB | Maximum IOPS |
| ----------------- | --------- | ----------- | ------------ |
| Basic NVMe SSD    | 500       | +10 / GB    | 10,000       |
| Standard NVMe SSD | 800       | +15 / GB    | 10,000       |

* Basic NVMe SSD provides lower baseline and scaling performance.
* Standard NVMe SSD offers higher baseline performance and faster scaling with capacity.
* Both disk types are capped at 10,000 IOPS.

#### 2. Throughput

Throughput characteristics are identical for both disk types:

* **Base Throughput**: 100 MiB/s
* **Scaling**: +0.25 MiB/s per GB of capacity

This ensures predictable bandwidth scaling as disk size increases.

#### 3. Burst Capability

**Standard NVMe SSD**

Standard NVMe SSDs support I/O burst, which temporarily increases performance:

* **Burst Duration**: Up to 20 seconds
* **IOPS Boost**: 1.5× current IOPS
* **Throughput Boost**: 2× current throughput

Burst is optional and **disabled by default**. You can enable it in the console, and it is suitable for handling short-term workload spikes.

**Basic NVMe SSD**

Basic NVMe SSDs do not provide burst capability by default. If you need burst performance, you can submit a request in the console to enable it.

### Conclusion

* **Basic NVMe SSDs** are suitable for cost-sensitive workloads with stable and moderate performance requirements.
* **Standard NVMe SSDs** are ideal for performance-sensitive applications that benefit from higher baseline performance and burst capability.

## Snapshot

Snapshots are point-in-time copies of your disks that capture their exact state, including files, system settings, and data. Use snapshots to back up your data for disaster recovery or testing.

* Automatic snapshot: the snapshot created automatically by the snapshot schedule.
* Manual snapshot: the snapshot created manually by the user.

### Snapshot Schedule

A snapshot schedule is an automated feature that regularly creates snapshots of your disks at predefined intervals, helping you protect data, simplify backups, and support disaster recovery.


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