Re: [gentoo-server] Can't mount root device (PERC 5/i)

[Patrik Jansson]

Christian Affolter wrote:
> Hmm, are you sure that your RAID has been recognized correctly? In case
> you don't have another RAID-set or a standalone disk/CD Rom, your
> RAID-set should be accessible as /dev/sda. So what's behind /dev/sda in
> your case?
No, I'm not. But I cannot access /dev/sda.
 From a terminal (LiveCD booted):
# fdisk /dev/sda
Unable to open /dev/sda

I may access /dev/sdb though (that's why the I installed Gentoo on sdb).

> So, to summarize: Check that your RAID set has been recognized properly
> before installing with the live-CD. Investigate why you only have one
> SCSI device in contrast to two on the live CD (missing SCSI CD-ROM
> support?).

I'm not sure how to do that. I'm not even sure if /dev/sdb is the actual 
RAID or just one of the drives? But when I come to think about it... 
when I try to boot the system, the Dell server actually boots from the 
logical drive and it do find the kernel, hence /dev/sdb is infact the 
RAID, right?
I also removed one of the drives, tried to boot (it finds the kernel), 
then I removed the other drive and rebooted and it still finds the kernel).

Steve Dommett wrote:
 > At this point does an 'lsmod' give any further clues?  For instance is
 > the LiveCD using the same driver for the RAID you are expecting to use
 > after the reboot?
lsmod gives one interesting module: megaraid_sas (if I recall 
correctly). And I guess this is one of the many LSI entries in kernel 
configuration, and I have tried enabling them all.

 >> sda: unknown partition table
 > Ouch!  Something is very wrong here.  I don't think you're going much
 > further until this one gets fixed.
I agree, something is wrong indeed!

 > Are you sure you're running the same driver for the card as was used
 > during the install?
Not at all and I don't know how to figure that out either. I was told to 
check /sys/ from the LiveCD and check which module was used for /dev/sdb 
  but I couldn't find anything (that I found) interesting.

 > Maybe you could try using genkernel to build the kernel, which will
 > also create an initrd to autoload most needed modules just like the
 > LiveCD.

I have tried that too! I have also tried genkernel and modified it to 
build support for LSI drivers.

 > Also, I doubt if this is necessary with a hardware RAID controller,
 > but perhaps emerge'ing device-mapper is necessary.   Perhaps also
 > mdadm too, but I'm even more doubtful about that one.

I can't see how this could make any difference when I can't even mount 
the root device? Anyway, I'm desperate and will try this as soon as I can.

Thanks for your help,
-Patrik
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