[parisc-linux] Re: Added a new SCSI disk, hda became hdb

[parisc-linux] Re: Added a new SCSI disk, hda became hdb

[Carlos O'Donell]

On Sun, Aug 24, 2003 at 09:13:40PM +0200, Ralf Hildebrandt wrote:
> Hi!
> 
> Today I added a new SCSI disk, and hda -- my bootdisk -- became hdb -- no
> matter which SCSI ID I chose for the new disk.
> 
> The old disk has ID 6, and I can do whatever I want, once I add the new
> disk, I cannot boot, since the kernel doesn't find it's rootfs on hda
> -- since it's hdb now.
> 
> How can I add a new physical disk as hdb ?

Put the disks in the reverse order?

An example is that any A500 or rp2430 labels the drives as 'scsia' and
'scsib', but linux finds them in the reverse order. When only one drive is
in 'scsia' it's sda, but when a second drive is added to 'scsib' the
order is reversed ('scsia' becomes sdb and 'scsib' becomes sda).

c.

Re: [parisc-linux] Re: Added a new SCSI disk, hda became hdb

[Matthew Wilcox]

On Sun, Aug 24, 2003 at 04:38:57PM -0400, Carlos O'Donell wrote:
> Put the disks in the reverse order?
> 
> An example is that any A500 or rp2430 labels the drives as 'scsia' and
> 'scsib', but linux finds them in the reverse order. When only one drive is
> in 'scsia' it's sda, but when a second drive is added to 'scsib' the
> order is reversed ('scsia' becomes sdb and 'scsib' becomes sda).

This is because HPUX uses the ANSI-approved scan order -- 7,6,5,...,0
and Linux uses the PC-compatible scan order -- 0,1,2,...,7.  It's kind
of possible to control it by setting shost->reverse_ordering but it's
not easy to set this in any reasonable way.

-- 
"It's not Hollywood.  War is real, war is primarily not about defeat or
victory, it is about death.  I've seen thousands and thousands of dead bodies.
Do you think I want to have an academic debate on this subject?" -- Robert Fisk

Re: [parisc-linux] Re: Added a new SCSI disk, hda became hdb

[Grant Grundler]

On Sun, Aug 24, 2003 at 10:42:12PM +0100, Matthew Wilcox wrote:
> This is because HPUX uses the ANSI-approved scan order -- 7,6,5,...,0

Not true. HPUX scans the SCSI bus from 0-7 for narrow or 0-15 for wide.

Under HPUX, SCSI controllers are assigned instance numbers and the
kernel records those in /stand/ioconfig. The SCSI controller will
get the same instance number after reboot regardless of other IO
devices changing.

grant