Re: USB HDD boot panic (2.6.31)

From: Calvin Walton
Date: Sun Sep 27 2009 - 13:45:45 EST


On Fri, 2009-09-25 at 14:47 +1000, Ben Ryan wrote:
> I've a question regarding boot from USB-attached IDE HDD under 2.6.31
> (slackware/lilo).

> From what I can gather the USB drivers aren't finished initialising before
> the disks are enumerated and mapped to /dev.
>
> Is this a known, current issue?
> Does anyone have a patch that can help? If so, why isn't it mainlined?
> (Please CC responses!)

This is a bit of a known issue, because USB simply doesn't have a way of
letting you know when scanning for devices has been completed. Current
versions of linux have a simple workaround: add "rootwait" to your
kernel command line in LILO.

(from Documentation/kernel-parameters.txt:)
rootwait [KNL] Wait (indefinitely) for root device to show up.
Useful for devices that are detected asynchronously
(e.g. USB and MMC devices).

Alternately, you can use an initramfs which is set up to wait for the
device to appear. The rootwait option is off by default in order to
speed up booting under normal circumstances.

> Thanks
> Ben

--
Calvin Walton <calvin.walton@xxxxxxxxx>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/