Drives Missing When HBA is Moved To Another PCIe Slot


New Member
Mar 21, 2020
Hi, I have several drives connected to a AsRock X470D4U motherboard (3 PCIe slots) using HP H220 HBA (MPT2BIOS-, IT mode) and SuperMicro BPN-SAS-216A backplane. The drives are configured into a ZFS array in Ubuntu 19.10, and `lsblk` and `zpool status` both shows all the drives as expected.

However, when I move the H220 HBA from the middle PCIe slot (PCI slot #5) to either of the other slots (#4, $6), all the drives are suddenly missing in Ubuntu. `lsblk` shows that all drives connected to the HBA are missing, and `zpool status` shows that no pool exists. The strange thing is that when the system first boots, the MP2BIOS boot screen for the HBA shows that all drives are detected, but Ubuntu is not able to see them.

Moving the HBA back to the middle PCIe slot allows all the drives to be detected again inside Ubuntu.

Is there a setting that should be set such that all drives can be detected inside Ubuntu when the HBA moved to other slots?




Well-Known Member
May 27, 2019
Austin, TX
What CPU are you using? Is it a Matisse?
If so per the motherboard manual:
For Matisse CPU users, if you want to use the PCIE4 slot, please first switch the PCIe x16 slot to [2x8] in the BIOS settings: Go to “Advanced” > “AMD PBS” > “PCIe x16/2x8/4x4 Switch” > select “[2x8]” and press F10 to save and exit. For more information, please see Chapter 3.3.9 AMD PBS
Also not super familiar with the option of pt chip vs cpu but it could also be the switch setting for pcie4:
PcieLanes_4_7_Switch: [PT] Pcie Lanes route to PT CHIP; [CPU] Pcie Lane route to CPU PCIE.
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