After upgrading my homelab to vSAN 6.6 I noticed that my memory usage suddenly jumped up around 2.5 times normal consumption. Wondering if I had missed something I went back through and read the release notes with more focus and tracked down this tidbit:
- Object management improvements (LSOM File System) – Reduce compute overhead by using more memory. Optimize destaging by reducing cache/CPU thrashing.
There it is, in plain english, vSAN 6.6 improves performance by utilizing more memory. Now for most folks in true production environments, a few extra GB won’t be noticed but if your lab only has 64GB of RAM, anything extra get’s noticed quickly.
Based on some calculations I’ve been able to use it looks like the RAM consumption roughly doubles what it was before. The original formula for calculating RAM usage could be found here from VMware:
I spoke to a few folks internally at VMware and indeed the numbers will shortly be updated to reflect the new changes. One thing to note based on my home tests, enabling or disabling Dedup, compression and the new encryption features has no impact on the memory changes.
Make sure to plan accordingly when thinking about upgrading to vSAN 6.6