Re: Linix-3.6.3 sda, sdb drives in reverse order (with a USB 2.0 drives and a monolithic kernel configuration)

[Chris Friesen <chris.friesen@genband.com>]

On 10/26/2012 01:43 PM, Wallak wrote:
> Chris Friesen wrote:
>> On 10/25/2012 04:49 PM, Wallak wrote:
>>> I've a very annoying behavior with the linux-3.6.x kernels release, and
>>> a monolithic configuration. The USB 2.0 drives are mapped first with
>>> /dev/sda, /dev/sdb... devices, and than the SATA AHCI drives come after.
>>> This is out of order with the BIOS configuration and breaks a program
>>> like lilo. This is also annoying when we use a static partition mapping.
>>>
>>> Linux-3.5 works fine. Where this bug come from ? Is this a patch to get
>>> the old, and classical behavior ?
>>
>> As you have discovered it's fragile to rely on /dev/sd* names since a
>> BIOS update, kernel update, or motherboard replacement could
>> conceivably cause them to change.
>>
>> Better to use something like partition labels that you control and
>> that don't change.
>>
>> Chris
>>
> You are right, when we have a configuration with a lot of drvies and
> adapters SATA, old SCSI,.. etc. the order may change. But having the
> main SATA hard drive defined, as the BIOS boot device, behind external
> and removable USB drives is in my opinion a bug.And may lead to security
> issues (drives with the same label, etc...).
>
> Using =LABEL, or =UUID with a bootloader like grub or lilo, save the the
> boot device mapped drive partition number , and so booting on an older
> kernel like linux 3.5 will fail. If we remove the external USB drive,
> the boot process will fail too...
>
> So such a bug have to be fix.

If you specify "root=LABEL=<label>" as part of the kernel boot args in 
grub does it not check the label at boot time?

Chris