How to force a (SATA) drive to be sda and the PATA one sdb

[Alfredo Ferrari]

On Wed, 3 Oct 2007, ed at hp.uab.edu wrote:

> On Wed, 3 Oct 2007, Alfredo Ferrari wrote:
>
>> Hi
>> I have the following problem:
>> 
>> a) a laptop with a SATA drive
>> b) a modular bay in the same laptop where I can fit a DVD, a battery
>>   or a PATA drive
>> 
>> If the PATA drive is there Fedora 7 recognizes it as /dev/sda and the SATA 
>> one as /dev/sdb. Without the PATA one, the SATA one is obviously /dev/sda. 
>> I would like to find a way to force the SATA one to be /dev/sda always: 
>> using labels is only mitigating the issue of the (main) disk flipping name, 
>> since some partitions are mounted via autofs which does not accept labels, 
>> and others are Windows ones which again cannot be mounted by labels at 
>> least to my knowledge.
>> 
>> In short, is there any mean (kernel parameter?) to force the SATA drive 
>> come first? BTW on Fedora Core 6 this issue was never present.
>> 
>
> Alfredo, I had the same problem when I added a SCSI controller into the 
> computer. The SCSI module was loaded first, then the SATA module. This bumped 
> the SATA drive that was sda to sdb, and nothing worked right.
>
> Solution: extract the initial ramdisk, edit the 'init' script, and reorder
> the module loading. Make sure the module for the sata is loaded before the 
> ide module.
>
> Now, I am not familliar with the PIDE modules, so you are on your own there. 
> But I would look for a line like
>
> insmod /lib/ide-scsi.ko
>
> and put it after a line like: ( since I have the NVidia chipset)
>
> insmod /lib/sata_nv.ko
>
> shout out again, if you don't know what I'm talking about when I say 'initial 
> ramdisk'
>
> Otherwise: Think again about labels, that's what they are for. And you have 
> already booted grub, and grub found the initial ramdisk... That may be all 
> you need.
>
> ed
>

Thanks a lot for the answer. I tried to work with the initial ramdisk, I 
managed to edit the init and, sigh, there is no ide module loaded, 
apparently the libata + ata_piix do both PATA and SATA in recent kernels, 
so apparently there is no obvious way to get the disks in the "right" 
order. Googling a bit I found other people complaining that PATA's are
recognized before SATA's now... so I am still with my problem.
Labels are fine for ext3 partition and no automount, while I have Windows 
partitions as well, and a lot of partition with automount (just because
the second disk is there sometimes yes sometimes no)

                     Thanks a lot for the help
                       Alfredo Ferrari

>

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|  Alfredo Ferrari                         ||  Tel.: +41.22.767.6119         |
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