Impact/Risks:
The enhancement aims at reducing the read IO latency and improving read IO performance when a VM is running on a SE Sparse snapshot.
You can expect better read throughput compared to earlier releases without using additional computing cost.
The quantum of improvement depends on the nature of work load ( read vs write), number of virtual disks per VM and underlying storage (all-flash, magnetic disk , NVMe etc). Based on our internal tests we see significant improvement (compared to earlier releases) for read IO on different backend storages.
Additional considerations:
- Improvement would be seen if size of the base disk is large enough (> 500GB). For very smaller disks there will be no significant improvement.
- Improvements are done specifically for one level of snapshot.
- Improvements will be higher if the workload is predominantly read. For example database workloads which typically have 70% read-30% write mix will also see an improvement.