Introduction
This document describes how to use the KAE compression and decompression functions on the Kunpeng server running the openEuler OS to accelerate virtual machine (VM) live migration.
VM live migration allows a VM to be migrated from one physical host to another without interrupting the VM running. To reduce the data volume transmitted during migration, compression technologies (for example, zlib library) are usually used on the source physical host to compress memory pages before transmission, and then the memory pages are decompressed on the target physical host, thereby speeding up the VM live migration.
The Kunpeng Accelerator Engine (KAE) is a hardware acceleration solution based on the new Kunpeng 920 processor model. It includes the compression module KAEzip, which can significantly reduce processor consumption and improve processor efficiency. KAEzlib is a standard zlib interface provided by the KAE compression module. It uses the Kunpeng hardware acceleration module to implement the Deflate algorithm and works with the lossless user-mode driver framework. Therefore, KAE can replace the native zlib library to accelerate VM live migration.
Before configuring the KAE-accelerated VM live migration feature, learn the specifications, supported version, license requirement, constraints, and application scenarios of this feature.
Specifications
Supported VM specifications include but are not limited to 2 vCPUs and 8 GB, 4 vCPUs and 8 GB, 4 vCPUs and 16 GB, 8 vCPUs and 16 GB, 16 vCPUs and 32 GB, and 32 vCPUs and 64 GB.
When the native zlib library is enabled during the Redis pressure test, live migration is restricted by the VM specifications and the number of live migration threads.
- VMs of 2 vCPUs and 8 GB, and live migration threads fewer than 32.
- VMs of 4 vCPUs and 8 GB, and live migration threads fewer than or equal to 4.
- VMs of 4 vCPUs and 16 GB, and live migration threads fewer than or equal to 4.
- VMs of 8 vCPUs and 16 GB, 16 vCPUs and 32 GB, and 32 vCPUs and 64 GB, and live migration threads fewer than or equal to 3.
Version Requirements
- Version: For Arm-based KVM and QEMU virtualization platforms, only libvirt 10.0.0 and later versions, and QEMU 6.2.0 are supported.
- License: KAE license.
- The application environment must meet the software and hardware environment requirements supported by KAE.
- For details, see Table 2 OS and software requirements.
Application Scenarios
VM live migration applies to load balancing, hardware maintenance, and disaster recovery (DR) high availability (HA) scenarios. It dynamically adjusts VM distribution to prevent a single physical host from being overloaded and improve resource utilization. VMs can be migrated without interrupting services to maintain or upgrade the source host. In addition, when a host is faulty or its performance deteriorates, VMs can be quickly migrated to ensure service continuity.