Previous-generation local SSD FAQ
Previous-generation local SSDs are no longer available for purchase. This topic is for users who purchased these disks and continue to use them.
What is a local SSD?
Unlike basic disks that store three data replicas, local SSDs use RAID technology. This design does not protect against data loss if a physical server goes down. If you require high data reliability, implement data redundancy at the application layer.
What are the use cases for local SSDs?
Local SSDs provide high random input/output operations per second (IOPS), high throughput, and low latency. They are ideal for I/O-intensive applications, such as NoSQL databases, Massively Parallel Processing (MPP) data warehouses, and relational databases.
What is the performance improvement of SSD disks over basic disks, and what are the specific parameters?
Data disk: A local SSD data disk delivers 10 to 20 times higher performance than a basic disk. With a 4 KB I/O block size, it delivers 12,000 random read/write IOPS. With a 512 KB I/O block size, it provides a sequential read/write throughput of 300 MB/s.
System disk: When used as a system disk with a 4 KB I/O block size, a local SSD delivers up to 3,000 random read/write IOPS and a sequential read/write throughput of up to 80 MB/s.
Can I add a local SSD to an existing ECS instance or replace a cloud disk with a local SSD?
No. Because local SSDs cannot be attached remotely, you cannot add them to existing ECS instances or replace existing basic disks with them.
Are upgrades supported after purchase?
You cannot perform configuration upgrades on the disk, CPU, or memory of an instance that uses local SSDs for its system or data disks. Only bandwidth upgrades are supported.