mdadm starts before mpt2sas finds drives

[Jonathan Nieder]

reassign 664581 mdadm 3.2.3-2
affects 664581 + src:linux-2.6
quit

Ross Johnson wrote:

> I found a better workaround.  Let's move this to wishlist for mdadm.
>
> Workaround for my system is to put the following in /etc/default/grub:
>   GRUB_CMDLINE_LINUX="rootdelay=9"

Yep, this is a known problem described at [1].

> I would like a better solution, something that 1) forces mdadm to wait
> for all its components before assembling the arrays and continuing with
> the boot and 2) has a safety timeout to continue the boot regardless.

Makes sense.

It looks like there's been some work on this already[2], which was
backed out in version 3.1.4-1:

  * However, disable the incremental assembly upstream turned on in 3.1.3 for
    now, this will have to wait until after the squeeze release.

Michael et al: please feel free to reassign as appropriate.

> This could take the form of specifying what arrays need to be assembled
> at boot time (i.e. /dev/md0, /dev/md1, and /dev/md2), repeatedly polling
> every second to find what drives are available and to which arrays they
> belong, and a final timeout setting to continue with the boot attempt
> even if not all components are ready.  The above should also handle the
> case where a raided drive (like /dev/md1) is used as a component in
> another sofware raid that is needed for boot.

Probably the long-term fix will look like [3].

Ciao,
Jonathan

[1] http://wiki.debian.org/InitramfsDebug
[2] http://bugs.debian.org/521547
[3] http://bugs.debian.org/417118