[ale] Converting to RAID5 root

[Howard A Story]

Okay that is a software RAID.   I get a headache just looking.  From the 
error that your are getting I start to wonder if it is more system setup 
than RAID setup.  If your md1 is /  what is md2?  make sure you don't 
have /tmp or /etc, You know a directory that the system needs during boot.

LVM is a logical volume manager??  It allows you to span drives to see 
them as one. If I am not mistaken.  Isn't RAID 5 the about the same 
thing with fault tolerance?  Can you really do them both on the same 
partitions?

LOL  I just saw a good commercial...  VW   Time to unpimp the ride.


Chris Woodfield wrote:

>Yeah, I realized I wrote this in a bit of haste. Let me explain the  
>setup more clearly:
>
>I initially installed my linux distro on a regular ATA drive,  
>standard debian 3.0 defaults (root at /dev/hda1, /home on /dev/hda5).
>
>I then added three SATA drives to the system, with the intent of  
>migrating the system over to the raid array. GRUB sees these as (hd2)  
>through (hd4). The libata driver names then /dev/sda - /dev/sdc.
>
>I set up the following arrays on the three drives:
>
>md0 - sda1, sdb2 - RAID 1 array to load kernel, will mount as /boot.
>md1 - sda5, sdb5, sdc5 - RAID5 array to mount as /
>md2 - sda6, sdb6, sdc6 - RAID5 array hosting LVM partitions
>
>I solved the kernel panic issue already - I had incorrectly assumed  
>that the initrd image generated by make-kpkg would load the proper  
>SATA modules and autodetect my SATA drives. It didn't. So I commented  
>the initrd out of menu.lst, compiled libata and RAID support into the  
>kernel directly, and rebooted.
>
>The system now autodetects the arrays, and mounts /dev/md1 as the  
>root partition, but then bombs with this error immediately after  
>mounting /dev/md1 :
>
>"Warning: could not open inital console"
>
>And I'm clueless, again.
>
>Any ideas on that one?
>
>-C
>
>On Mar 5, 2006, at 9:26 AM, H. A. Story wrote:
>
>  
>
>>This defies my logic of RAIDS.   Is this a software RAID?  A RAID 1
>>requires at least 2 drives.  A RAID 5 requires at least 3 drives.  You
>>don't appear to have enough.  You would need a total of 5 drives for
>>this configuration.  Unless you were doing sometime of magic with
>>software RAID.  And that some how doesn't sound like a good idea.
>>
>>However if I am wrong I was reading something the other day about
>>initrd.  This would have to be loaded before attempting to mount the
>>root.  I THINK.  It needs to load the drivers for the RAID before the
>>kernel can boot.
>>
>>Chris Woodfield wrote:
>>
>>    
>>
>>>OK, here goes...
>>>
>>>I'm converting a standard one-drive debian sid installation to a 3-
>>>drive RAID. I current have both the original drive and the three SATA
>>>drives installed in the system. I've maid the raid partitions with no
>>>issues. I have three RAID partitions:
>>>
>>>md0	boot partition, RAID 1
>>>md1	root, RAID 5
>>>md2 	LVM volume, RAID 5
>>>
>>>What I'm trying to do at the moment is make sure I can boot off of
>>>the RAID set with md1 as the root partition. Here's the relevant part
>>>of menu.lst on the primary drive:
>>>
>>>title           Debian GNU/Linux, kernel 2.6.15.4 RAID
>>>root            (hd2,0)
>>>kernel          (hd2,0)/vmlinuz-2.6.15.4 root=/dev/md1 ro
>>>initrd          (hd2,0)/initrd.img-2.6.15.4
>>>savedefault
>>>boot
>>>
>>>title           Debian GNU/Linux, kernel 2.6.15.4 RAID (recovery  
>>>mode)
>>>root            (hd2,0)
>>>kernel          (hd2,0)/vmlinuz-2.6.15.4 root=/dev/md1 ro single
>>>initrd          (hd2,0)/initrd.img-2.6.15.4
>>>savedefault
>>>boot
>>>
>>>I've already copied all the filesystems over to the relevant RAID
>>>partitions. RAID is compiled into the kernel.
>>>
>>>By all appearances, GRUB is able to boot the kernel that lives on the
>>>md0 volume, but I get a kernel panic at the point where the system
>>>attempts to mount /dev/md1 as the root volume. The error reads:
>>>
>>>VFS: Cannot open root device "md1" or unknown-block(0,0)
>>>Please append a correct "root=" option
>>>Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-
>>>block(0,0)
>>>
>>>Is there something that needs to be set up prior to this mount
>>>operation (a boot arg, for example) such that the kernel knows how to
>>>assemble /dev/md1? Is this something that should be in the initrd
>>>that make-kpkg creates? Any other ideas?
>>>
>>>Thanks,
>>>
>>>-Chris
>>>
>>>_______________________________________________
>>>Ale mailing list
>>>Ale at ale.org
>>>http://www.ale.org/mailman/listinfo/ale
>>>
>>>
>>>
>>>      
>>>
>>_______________________________________________
>>Ale mailing list
>>Ale at ale.org
>>http://www.ale.org/mailman/listinfo/ale
>>
>>    
>>
>
>_______________________________________________
>Ale mailing list
>Ale at ale.org
>http://www.ale.org/mailman/listinfo/ale
>
>  
>