The usage mode of persistent memory on some re6p instance types can be configured. You can use the persistent memory as memory or local SSDs. This topic describes how to configure the usage mode of persistent memory.
Prerequisites
- The instance type is one of the following instance types:
- ecs.re6p.large
- ecs.re6p.xlarge
- ecs.re6p.2xlarge
- ecs.re6p.13xlarge
- ecs.re6p.26xlarge
- The image version meets one of the following requirements:
- Alibaba Cloud Linux 2
- CentOS 7.6 or later
- Ubuntu 18.10 or later
- SUSE Linux 12 SP4 or later
Background information
- Used as memory: You can move some data stored in regular memory to persistent memory, such as non-hotspot data that has lower requirements for access speed. Persistent memory offers large capacity at a low price per GiB and can help reduce the total cost of ownership (TCO) per GiB.
- Used as local SSDs: Persistent memory can be used as local SSDs to provide ultra-high performance and read/write latency as low as 400 nanoseconds. Therefore, you can choose persistent memory for core application databases that require consistent response time (RT). You can replace cache disks with persistent memory to obtain higher IOPS, higher bandwidth, and lower latency. This can improve the business performance of the entire cluster.
Notice The reliability of data stored in persistent memory depends on the reliability of
persistent memory devices and the physical servers to which these devices are attached.
This increases risks of single points of failure. To ensure the reliability of application
data, we recommend that you implement data redundancy at the application layer and
use cloud disks for long-term data storage.
The following configurations are used in this example:
- Instance type: ecs.re6p.2xlarge
- Image: Alibaba Cloud Linux 2.1903 LTS 64-bit
Use persistent memory as memory
When persistent memory is used as memory, its core capability is to support character addressing. The space of persistent memory and regular memory is independent of each other and is not merged. You can also use memkind to allocate memory space. For more information about how to use memkind, visit memkind.