I have this issue.
#1 random nvme 256gb
#2 Corsair MP510 1TB (900GB)

#3 samsung 980 1TB (930GB)


I want to increase my cache pool and can harvest 2 ssds from my pc. both roughly 1tb.
I only have 2 nvme slots, so i have to first move it to ssd #2 and mirror it this way. and after that replace #1(256gb) with ssd #3

Now i am unable to mirror my boot drive using the unraid tools on 7.3.1
And also moving back from internal boot to usb temporarily is failing for me. What do i need to do?
Use clonezilla and clone the nvmes?

I just want to have a bigger cache pool. and reliability for failing.

Currently my idea is creating a new unraid usb boot drive. Remove the current boot drive and make sure that both ssd #2 and #3 are in place

Please post the diagnostics to see the current status