2.6.0 and auto geometry resizing?

2.6.0 and auto geometry resizing?

[PeteVine]

I've got this problem with 2.6 kernels, namely I can't use my RAID 
partitions as they are not detected at boot.  I've tracked the issue
to what I believe is auto geometry resizing.

With 2.6 cfdisk shows:

hdc1           Boot, NC       Primary     OnTrackDM6                  33814,13                                   
					Pri/Log     Free Space     		     26205,75


Whereas with 2.4 there's no resizing: 

hdc1                    Primary   Linux swap                        254,99     
hdc5                    Logical   Linux raid autodetect      	98,71    
hdc6                    Logical   Linux raid autodetect		254,99    
hdc7                    Logical   Linux raid autodetect             2599,19    
hdc8                    Logical   Linux raid autodetect            56812,01

The disk in question used to be jumpered to 32 GB 
a few years ago, then treated with ontrack to get the full
capacity. Later the jumper was removed and the disk was
partitioned in Linux 2.4 as shown above. Now, 2.6 even with
auto geometry resizing not compiled in, insists on 
resizing the disk. Any ideas how to get around the problem?

Re: 2.6.0 and auto geometry resizing?

[Andries Brouwer]

On Sun, Dec 21, 2003 at 04:28:50PM +0100, PeteVine wrote:

> I've got this problem with 2.6 kernels, namely I can't use my RAID 
> partitions as they are not detected at boot.  I've tracked the issue
> to what I believe is auto geometry resizing.
> 
> With 2.6 cfdisk shows:
> 
> hdc1           Boot, NC       Primary     OnTrackDM6                  33814,13                                   
> 
> Whereas with 2.4 there's no resizing: 
> 
> hdc1                    Primary   Linux swap                        254,99     

It is clear what happens. Both kernels see different partition tables.
You did not show the 2.4 boot messages, but no doubt they will mention
something about the boot manager shift.
Give 2.6 the appropriate boot parameter and all will be fine.

What parameter? Quoting from ide.c:
 * "hdx=remap63"        : add 63 to all sector numbers (for OnTrack DM)
 * "hdx=remap"          : remap 0->1 (for EZDrive)

So if you have OnTrack you need "hdc=remap63".

Andries