[arch-general] Arch, blk-mq and megaraid_sas

[Randy DuCharme]

Greetings,

I'm still fooling around with this problem (scsi_mod.use_blk_mq=y fails to
boot) but made *some* progress.  I've found that it takes about 20-25
seconds after it dumps me into an emergency shell for the disk device nodes
to show up, but when they do I can mount the root slice to /new_root, exit,
and it boots and runs fine with blk-mq enabled.

The thing is, it finds my root drive, which is attached to the first SATA
port as /dev/sdcX, putting the 2 arrays I have on the controller as
/dev/sda1 and /dev/sdb1 and no amount of BIOS fiddling seems to help.
(board's an ASUS Crosshair-V Formula-Z)  I've even disabled the controller
as a boot candidate in CMOS and this behavior still exists.

To further confound me; for grins I set up RHEL-7.5 on another drive and
for some reason I don't understand, it finds the first SATA drive as
/dev/sdaX.  Is there some way to force Arch to do the same.  I'm rather
curious if that'll solve the boot issue I'm experiencing with this system.

Many thanks!

-- 
Randall DuCharme (Radio AD5GB)
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