# RAID1: sda3 does not have a valid v0.90 superblock

## ID

I'm trying to do a upgrade install of RAID 1 using the instuctions on http://gentoo-wiki.com/HOWTO_Migrate_To_RAID.

My first disc is sda (with data on it) and the second is sdb.

The problem is that I can't seem to mount the /dev/md3 as root system.

 *Quote:*   

> md: Autodetecting RAID arrays.
> 
> md: invalid raid superblock magic on sda3
> 
> md: sda3 does not have a valid v0.90 superblock, not importing!
> ...

 

I have tried adding the -e 0.90 option to the mdadm command, but it doesn't resolves anything  :Sad: 

 *Quote:*   

> mdadm -C /dev/md3 -e 0.90 -l 1 -n 2 missing /dev/sdb3

 

this is my /etc/fstab (on the sda)

 *Quote:*   

> /dev/sda1               /boot           ext2            noauto,noatime  1 2
> 
> /dev/sda2               none            swap            sw              0 0
> 
> /dev/sda3               /               reiserfs        noatime         0 1
> ...

 

and this is the one in /mnt/raid-md3/etc/fstab:

 *Quote:*   

> /dev/sda1               /boot           ext2            noauto,noatime  1 2
> 
> /dev/sda2               none            swap            sw              0 0
> 
> /dev/md3                /               reiserfs        noatime         0 1
> ...

 

I have only choosen to mirror (RAID1) sda3. So I should result in a mount of /dev/md3 but it keeps saying /dev/sda3 probably because of above error during boot. 

Can I savely change the superblock on sda3 somehow without distroying the data on it?

And how can I see with df if i'm running with a degraded RAID on /dev/sdb3? /dev/md3 I suppose?

Kernel settings are same as on the http://gentoo-wiki.com/HOWTO_Migrate_To_RAID site.

Oh, yes.. this i my mdstat

 *Quote:*   

> dingetje ~ # cat /proc/mdstat
> 
> Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
> 
> md3 : active raid1 sdb3[1]
> ...

 

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## ID

Hmm, ok.. Still found nothing  :Sad: 

Maybe "sfdisk -d /dev/sdb | sfdisk /dev/sda" just works? cause I already copied it to sdb3 and the superblock will also be recreated?? Or am I not possible to boot anymore then?

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## ID

Ok, still having problems.. But... according to http://gentoo-wiki.com/HOWTO_Gentoo_Install_on_Software_RAID I have change the grub.conf to:

 *Quote:*   

> title=Gentoo Linux 2.6.24-r4
> 
> # Partition where the kernel image (or operating system) is located
> 
> root (hd0,0)
> ...

 

And dmesg now gives me the same errors twise now:

 *Quote:*   

> md: Autodetecting RAID arrays.
> 
> md: invalid raid superblock magic on sda3
> 
> md: sda3 does not have a valid v0.90 superblock, not importing!
> ...

 

but df gives me:

 *Quote:*   

> Filesystem           1K-blocks      Used Available Use% Mounted on
> 
> /dev/md/3            243586032   1680932 241905100   1% /
> 
> udev                     10240        60     10180   1% /dev
> ...

 

Which looks good to me  :Wink: 

So, what is going on here... Is this suppose to do this?

Well.. I think i will try to go on cause this is the md mount.. as it suppose to be.

So.. so far so good?  :Wink: 

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## ID

Well, I unstand some things better now.. Probably the autoconfig just detects for fd partitions I guess... In my grub.conf I told the kernel what the partitions are and so it works.... But now i'm stuck again because I need to do:

 *Quote:*   

> 
> 
> sfdisk -d /dev/sdb | sfdisk /dev/sda
> 
> 

 

But sda1 and sda2 are in use (boot / swap). And what I really want is just mirror the third partition.. and sfdisk -d /dev/sdb3 | sfdisk /dev/sda3 will not work.. anyone got maybe a trick to to this without sfdisk?

This upgrade is a horror... Maybe I should't have upgraded the system after all... And just started from scratch on a clean system.. But then again I wouldn't have understand the whole software raid things anyway.

BTW: Is the subject title frighting people off or some?

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## ID

Well... I found out that it just works...

 *Quote:*   

>  * I did not made the partition of type fd
> 
>  * I did not do the sfdisk -d /dev/sdb | sfdisk /dev/sda but skipped that one... I think this was "just" for copying the partition type info
> 
>  * mountpoint is /dev/md/3 and not /dev/md3
> ...

 

So, I think it's fixed..

 *Quote:*   

> Every 1.0s: cat /proc/mdstat                            Mon Apr  7 07:30:06 2008
> 
> Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
> 
> md3 : active raid1 sda3[2] sdb3[1]
> ...

 

I think i can disable some Peronalities in the kernel though.. I only need raid1 ..

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## ID

ANd now just wait for the kernel to get superblock v1.0 support?

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