Disk
UCloud-Global currently offers five types of disks for cloud hosts: Local ordinary disk, Local SSD disk, Ordinary cloud disk, SSD cloud disk, and RSSD cloud disk.
Type Introduction
Cloud Disk
As a basic block storage product for cloud computing scenarios, it provides persistent storage space for cloud hosts as block device hard drives. It has an independent life cycle, based on network distributed access, providing data large capacity, high reliability, scalable, easy to use, low-cost hard drive for cloud hosts. UCloud-Global currently offers SSD cloud disk and ordinary cloud disk as cloud disk options.
Local Disk
A virtual hard disk on the same host as the cloud host's CPU/memory, characterized by lower latency. Its life cycle is consistent with the cloud host, and it cannot be bound or unbound. RAID is used for data protection to prevent data loss. UCloud-Global currently offers SSD local disk and ordinary local disk as local disk options.
Selection Guide
Disk Comparison Overview
Detailed Comparison
| Parameter | RSSD Cloud Disk | SSD Cloud Disk | Ordinary Cloud Disk | Local SSD Disk | Local Ordinary Disk |
|---|---|---|---|---|---|
| General Description | New cloud disk product, ultra-high performance, latency only 0.1 milliseconds. Currently only supports Outstanding series cloud hosts | Outstanding and stable comprehensive performance, suitable for most scenarios, also has a balanced price | Optional maximum capacity, suitable for low IO but redundant scenarios | Excellent performance and latency, the highest unit price | Local disk with IO optimization technology, has better IO performance than ordinary SATA disk |
| Recommended Scenarios | High-performance databases, Elastic Search searches and other low-latency I/O intensive applications | I/O intensive applications, relational databases, NoSQL databases, and other applications that cannot be satisfied with other ordinary disk performance | Log storage, large file sequential reading and writing, small relational databases, development test environment, Web servers | Large relational databases with application layer redundancy, NoSQL databases, high-frequency transactions, etc. | Small relational databases, various enterprise applications, data analysis, game servers |
| Underlying Media | SSD | SSD | SATA | SSD | SATA |
| IO Performance Reference | Stable 1200000 | Stable 24000 | Peak 1000 | Peak 80000 | Peak 8000 |
| Latency | 0.1ms | 0.5-3ms | 10ms | 0.3ms | 0.3ms |
| Redundancy Mechanism | 3 copies | 3 copies | 3 copies | 2 copies | 2 copies |
| Capacity | 20-32000GB | 20-8000GB | 20-8000GB | 20-1000GB | 20-2000GB |
Performance
Detailed Performance Parameters
| Parameter | RSSD Cloud Disk | SSD Cloud Disk | Ordinary Cloud Disk | Local SSD Disk | Local Ordinary Disk |
|---|---|---|---|---|---|
| Optional Capacity (Data Disk) | 20-32000GB | 20-8000GB | 20-8000GB | 20-1000GB | 20-2000GB |
| Random Read (IOPS) | min{1800+50 * capacity, 1200000} | min{1200+30 * capacity, 24000} | 1000 | 80000 | 8000 |
| Random Write (IOPS) | min{1800+50 * capacity, 1200000} | min{1200+30 * capacity, 24000} | 1000 | 15000 | 8000 |
| Sequential Read (MBps) | min{120+0.5 * capacity, 4800}MBps | min{80+0.5 * capacity, 260}MBps | 100 | 2000 | 150 |
| Sequential Write (MBps) | min{120+0.5 * capacity, 4800}MBps | min{80+0.5 * capacity, 260}MBps | 100 | 1000 | 150 |
| Average Latency | 0.1ms | 0.5-3ms | 10ms | 0.3ms | 0.3ms |
The IO performance of a virtual machine instance is linearly proportional to its CPU configuration. The more cores a virtual machine has, the higher the storage IOPS and throughput it can achieve.
- If the performance of the RSSD cloud disk does not exceed the IO storage capacity of the instance, the actual storage performance is determined by the performance of the RSSD cloud disk.
- If the performance of the RSSD cloud disk exceeds the IO storage capacity of the instance, the actual storage performance is determined by the storage performance corresponding to the instance.
- If the number of instance cores is not in the following table, the instance performance is the maximum performance that does not exceed the number of cores. For example, if the CPU has 50 cores, its storage IO performance is the same as that of 48 cores.
| vCPU (Core) | Storage IOPS (10,000) | Storage Throughput (MB/s) |
|---|---|---|
| 1 | 1.8 | 75 |
| 2 | 3.8 | 150 |
| 4 | 7.5 | 300 |
| 8 | 15 | 600 |
| 12 | 22.5 | 900 |
| 16 | 30 | 1200 |
| 24 | 45 | 1800 |
| 32 | 60 | 2400 |
| 48 | 90 | 3600 |
| 64 | 120 | 4800 |
Test Method
Refer to Test Tool (opens in a new tab)
Model/Feature Support
Model Support
| Model | System Disk | Data Disk |
|---|---|---|
| Outstanding Cloud Host Series | RSSD Cloud Disk | Ordinary Cloud Disk/SSD Cloud Disk/RSSD Cloud Disk |
| General Type N | SSD Cloud Disk | Ordinary Cloud Disk/SSD Cloud Disk |
| General Type N | Ordinary Local Disk | 1 Ordinary Local Disk, can be stacked with multiple cloud disks |
| General Type N | SSD Local Disk | 1 SSD Local Disk, can be stacked with multiple cloud disks |
| High Frequency Type C | SSD Local Disk | 1 SSD Local Disk, can be stacked with multiple cloud disks |
| GPU Type G | SSD Cloud Disk | Ordinary Cloud Disk/SSD Cloud Disk |
| GPU Type G | SSD Local Disk | 1 SSD Local Disk, can be stacked with multiple cloud disks |
| GPU Type G | SSD Cloud Disk | Ordinary Cloud Disk/SSD Cloud Disk |
Feature Support
| Disk Type | UDataArk | Regular Snapshot |
|---|---|---|
| RSSD Cloud Disk | Supported | Supported |
| SSD Cloud Disk | Supported | Supported |
| Ordinary Cloud Disk | Supported | Supported |
| SSD Local Disk | Not Supported | Not Supported |
| Ordinary Local Disk | Supported (System disk and data disk need to be enabled simultaneously) | Not Supported |
FAQ
Why can't I see the disk type I want in some available zones?
The above disk types have not been launched in some data centers, or are restricted from application due to inventory reasons. If you find that you cannot select the required disk, please contact technical support.
Can a cloud host mount multiple local disks?
By default, a cloud host includes one system disk and one data disk. A host can only mount one local data disk, and it cannot be unmounted and mounted to another host.
However, a host can mount 26 cloud data disks, which can be freely unmounted.
Is the system disk expansion feature supported?
SSD Cloud Disk: Expansion from 20-500G is supported, free for 40G or less, and standard disk fees are charged for more than 40G.
Ordinary Local Disk/SSD Local Disk: Expansion from 20-100G is supported, free for 40G or less, and standard disk fees are charged for more than 40G.