Supermicro BPN-SAS2-846EL with SAS3 HBA in dual channel mode

[alavr]

Hi All,

I have some old Supermicro 4U chassis with SAS2 backplane (BPN-SAS2-846EL).
There is no problems in dual channel mode with SAS2 controllers: LSI 9211 or Adaptec ASR7805 in HBA mode.
Some time ago I decided to upgrade the controllers and purchased several LSI3008 units.
After connect LSI SAS 3008 (9300-8i) IT-mode = SAS3 to backplane BPN-SAS2-846EL = SAS2 in dual mode,
I have duplicated disks: 48xHDD instead 24xHDD.

Summary: dual channel mode SAS2 HBA controllers <-> SAS2 backplane Supermicro = no problem
dual channel mode SAS3 HBA controllers <-> SAS2 backplane Supermicro = problem disks duplicated

Perhaps someone has encountered such a problem. Is there a solution or ideas?

ps. Maybe someone have SAS3 HBA controller connected to SAS3 Supermicro backplane (BPN-SAS3-846EL) in dual channel mode?

 

[sko]

This is an dual expander backplane; if you wire 2 HBAs to it, you will run it in a multipath configuration and need to configure MPIO. In essence, you need to configure which 2 device nodes are actually the same device via different paths; this is done via gmultipath(8).

 

[ralphbsz]

This is an dual expander backplane; if you wire 2 HBAs to it, you will run it in a multipath configuration and need to configure MPIO.

Agree.

And if you don't want to bother with setting up multipath, you need to at least be very careful to make sure every physical disk is only accessed (mounted) from one path.