How do I go about SSD caching a MDADM RAID array with SSDs?
I setup Ubuntu 18.04.3 Server on an SSD. Then I made a RAID 6 array with MDADM. I have 2 spare NVMe 970 EVO drives I want to use to cache the RAID. I have not found a solid answer on how to do this.
I have tried ZFS in the past on Ubuntu 18.04 server but had an issue where upon reboot, the ZPool would not be added unless I manually added the pool which as you can imagine is not particularly wanted in a production environment.
I currently have the 2 NVMe drives also setup in MDADM as a RAID1 array to simulate a ZFS Cache pool but dont know where to go from there.
Should I make an LVM2 Volume Group of the RAID 6 array and the another Volume Group for the Cache pool? Then setup lvmcache between the 2?
Not sure how to do that exactly.