So, I work a fair amount in storage and on a number of file systems however on some storage appliances I have been building I use PCI nvme cards as either a block layer caching device or as a lvm cache for an xfs volume containing a number of spindles in a Raid 6 - I have seen massive improvements in overall storage performance using caching, which has allowed me to use these appliances for heavy video workflows and virtualisted environments etc...
Im curious if anyone else out there is using caching and what caching mechanisms are you using ? Are you tweaking the blockdev sizes etc and the queing particularly on the SSD/Nvme layer ?
