Advances, Systems and Applications
Table 1 Comparison table of pre-copy and post-copy based on Performance metrics
From: A critical survey of live virtual machine migration techniques
Performance metrics | Pre-copy technique | Post-copy technique |
|---|---|---|
Preparation time | It includes all the modified pages in iterative memory copying phases | Negligible |
Downtime | It includes transferring any remaining dirty pages | It includes transferring another minimal execution state |
Resume time | Re-schedule the target VM at the destination server and remove the memory pages at the source server | Majority of post-copy approach transfer the VM state and most of the memory pages in this period |
Pages transferred | Transfer number of pages during preparation time period | Transfer number of pages during resume time period |
Total migration time | More | Less |
Performance degradation | High due to the tracking of dirtied pages for write-intensive workloads | High due to servicing of faulty pages |