Michael

Replying to my own thread. The answer was that the SSD was connected using a usb3/usbC enclosure but went through usb3/usbA cable and so the pcie pass-through did not seem to work right. Direct connection of enclosure to thunderbolt via proper cable made mirroring work, no slowdowns and the new SSD is now fully functional. Whew. This stuff is really tricky to get right.

I started off with the need to clone the laptop drive to the new SSD and decided to use clonezilla. I have a small laptop with a 512 gig SSD (M.2 NVME). There is no way to mount another SSD in the chassis so I used an external usb enclosure to attach a 4 Tb M.2 NVME disk. The system has UEFI so I happily put clonezilla on a usb stick, booted everything into RAM, and told Clonezilla which disk to clone where. The first issue that I saw was that the cloning process became very slow, down to about 35...