scsi_mod.use_blk_mq (revisited)
(too old to reply)
Randy DuCharme via arch-general
2018-05-11 22:21:01 UTC
Well, I was trying the same thing but via GRUB_PRELOAD_MODULES (which
didn't work) so gave this a go.
Still didn't work. First I just added just "megaraid_sas" which failed to
solve it, so then I added a bunch. Just
about everything "(MODULES=(megaraid_sas xfs scsi_mod libcrc32c ahci
xhci_pci ohci_pci ehci_pci xhci_hcd
ohci_hcd ehci_hcd sr_mod sd_mod libata shpchp i2c_piix4 sp5100_tco k10temp
fam15h_power nouveau nvidia_drm nvidia) )"
but it still takes nearly 30 seconds for the sdX devices to appear with
blk-mq enabled. Strange.

Thanks for your thoughts though. I'm not done banging on it yet.

Kind regards
Greetings again,
I've been continuing to fool with this. I'm hoping someone smarter
than I
can shed a little more light on it. Here's what I've discovered since
last post.....
It seems that on my system, it takes more than the allowed 10 seconds
the disks to appear. I removed "quiet" from my boot command line and it
timed out looking for UUID=xxxx..... . So I looked for it and it
definitely was not there. None of the sdXx devices were. I looked
and yet again (ls /dev/sd*) and after about the 3rd or 4th attempt they
showed up. So then, I mounted /dev/sdc3 to /new_root/, typed 'exit' and
after a warning about possibly failing to run as a user instance, it
Any clues as to why this occurs? I'm trying to find a way to increase
pre-boot disk probe timer if possible. So far, all I've found are tips
about speeding up the boot process, not slowing it down.
Many thanks in advance.
In order for your drives to be detected the kernel modules needed by the
hardware must be loaded and active.
Your description matches a situation where some needed module is loaded
too late in the boot process.
Use lspci -k to determine which kernel modules are needed for your sata
/ raid controllers and add that one to the modules= line in
mkinitcpio.conf .
Incase it's unclear which module is needed, try the one that handles the
boot parameter (scsi_mod) .
Randall DuCharme (Radio AD5GB)
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