From: stryder@telenet.be.invalid   
      
   On Monday 19 November 2012 02:12, Adam conveyed the following to   
   alt.os.linux.mandriva...   
      
   > TJ wrote:   
   >   
   >> So I'm going from two IDE drives to a single IDE and a single SATA.   
   >> Should be interesting to see what kind of hoops I have to go through   
   >> to get this up and going.   
   >   
   > My "test system" from late 2007 came with one internal SATA drive, and   
   > I added an internal PATA drive.  [...]   
      
   That's a similar setup to what I have here in this machine.  The machine   
   was shop-assembled (as a promotion campaign) and came with a SATA disk.   
   However, I asked the guys at the shop to also put in the PATA disk from   
   my earlier machine - the one that "blew up".   
      
   The BIOS in this machine sees the PATA disk, but does not present it as   
   a bootable device.  However, strangely enough, when nothing at all is   
   installed on the SATA drive, or when the SATA drive is failing - as   
   happened to me a few months after I bought the machine - the BIOS will   
   continue to boot from the PATA drive instead.   
      
   The PATA disk came from my earlier, failing machine, and therefore it   
   has (32-bit) PCLinuxOS 2009.2 on it, /with/ a GRUB bootloader.  I have   
   installed Mageia 1 (64-bit) on the SATA drive, with Mageia's GRUB also   
   on the SATA drive.  I have also - for the sake of convenience - copied   
   over the kernels and initrds of PCLinuxOS to the /boot partition on the   
   SATA and added them to the Mageia bootloader.   
      
   When booting into PCLinuxOS, the PATA disk is listed as /dev/hda and the   
   SATA disk as /dev/sda.  When booting into Mageia, the SATA disk remains   
   /dev/sda but the PATA disk becomes /dev/sdb.  There are also /dev/sdc,   
   /dev/sdd and possibly even /dev/sde, but those are all for the built-in   
   card reader - which I never use, but anyway - and for USB thumb drives.   
      
   In my experience, when a SATA and a PATA disk exist in the same machine,   
   any modern kernel will consider the SATA disk to be /dev/sda and the   
   PATA disk /dev/sdb.  And if I were to put in a SCSI or SAS disk as well   
   - which would require a separate controller as the motherboard does not   
   have any of those - then that one would become /dev/sda.   
      
   The kernel seems to have its preferences and generally puts the higher   
   performing disk [*] before the others, although I cannot say that I have   
   read any documentation illustrating this, or anything about the   
   mechanism by which the kernel judges this.  Major and minor numbers on   
   SAS and SCSI disks are identical, and they possibly also apply to SATA   
   and USB storage media, and with newer kernels, PATA disks are now also   
   seen as SCSI disks.  So I don't think it's a matter of major and minor   
   numbers.  Someone else might be able to shed a light on this.   
      
      
   [*] The traditional order of performance is always SAS, SCSI, SATA,   
       PATA, USB.  I do not know where Firewire is situated in that order,   
       but I reckon it will be _behind_ SCSI.   
      
   --   
   = Aragorn =   
   (registered GNU/Linux user #223157)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)