Live Migration With Hardware Acceleration
Notes about Live Migration With Hardware Acceleration.
slides
video
Overview
- Live migration pain points
- VMs with memory write intensive workloads are difficult to migrate
- VMs with large memory size takes long time to migrate
- May consume large network bandwidth
- Existing solution: compression with CPUs
- Slow
- Consumes too many CPUs from host
- Our solution
- Offload the compression part to Intel QAT with efficient approaches
- Higher migration throughput
- Lower CPU utilization
- A common design ready for future more accelerators to join in
- Data Streaming Accelerator (DSA) and Intel Analytics Accelerator (IAX) coming on Sapphire Rapids CPUs
- Smart Selection
- Offload the compression part to Intel QAT with efficient approaches
QAT
QuickAssist Technology (QAT) accelerates cryptographic and compression workloads by offloading the data to hardware capable of optimizing those functions.
IAX
(Intel Analytics Accelerator)
Has compression capability
DSA
(Data Streaming Accelerator)
DSA is a high-performance data copy and transformation accelerator that will be integrated in future Intel® processors, targeted for optimizing streaming data movement and transformation operations common with applications for high-performance storage, networking, persistent memory, and various data processing applications.
Intel® DSA replaces the Intel® QuickData Technology, which is a part of Intel® I/O Acceleration Technology.
The goal is to provide higher overall system performance for data mover and transformation operations, while freeing up CPU cycles for higher level functions.
Smart Acceleration Support
- DSA compares the dirty memory, and sends the “diff” to the destination only
- Good when the guest only modifies a small part of a page
- Bad when the entire pages are changed
- Smart Acceleration
- Dynamically switch to use QAT/IAX compression or DSA diff during live migration using a prediction based on the compression ratio history and diff ratio history
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