Hello, I would like to ask for consideration of adding NVMe disk support to the caching layer in `dm-pcache`. At present, `cache_dev` only supports `pmem`.
From my perspective, extending `pcache` to support NVMe devices (along with an LRU-based eviction policy) could make it a strong alternative to `bcache` in certain use cases. For example, `pcache` appears to work without requiring the backing storage devices to be reformatted, which I see as a practical advantage. For my home server workloads, I experimented with `lvmcache`, but I found both writeback and read performance unsatisfactory compared to what I was hoping for. My test notes and benchmarks are available here for anyone interested: https://github.com/TheLinuxGuy/ugreen-nas/tree/main/experiments-bench Would adding NVMe support (and potentially configurable caching policies like LRU) be of interest to the project? I am happy to assist with testing or provide more detailed feedback from my benchmarks if that would be useful. Thanks for your time and consideration. Giovanni
