Comment 43 for bug 1626894

Maybe some symptoms with my old mainboard will be helpful for general debugging this issue:

-The drive was *sometimes* recognised fine at boot in first place, showed with "lspci" and "nvme list" would give me correct output
-After boot, the drive would go "missing" after a duration of approx. 5 to 1000 or more seconds for no obvious reason, here's what dmesg | grep nvme gave:

[ 37.805783] nvme 0000:01:00.0: Failed status: 0xffffffff, reset controller.
[ 37.825887] nvme 0000:01:00.0: Refused to change power state, currently in D3
[ 37.825934] nvme nvme0: Removing after probe failure status: -19
[ 37.825941] nvme0n1: detected capacity change from 1024209543168 to 0

Furthermore, this could be interesting:

-If I changed from default BIOS settings to overclocked ones, the NVME drive would not be seen by the _OS_ anymore
-If my HDD drive was going to sleep in Ubuntu (via hdparm), the NVME drive would get disconnected _instantly_, with dmesg showing the same output as above.

The two last effects were reproducible, they occured with kernels 4.4.0-53, 4.4.0-57, 4.4.0-58, 4.9.0. Especially hdparm -Y (or -y) /dev/myhdd would cause the NVME drive to become lost instantly.

Hope this may be of help.