[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: kubuntu vs fedora initrd init files



Mikkel responded:
To tell if Ubuntu does the same thing, you would have to do the same
type of install. The reordering of the disks is because of two
reasons. The first is because of the BIOS, and affects Grub. When
you boot from a USB device, that device becomes BIOS drive 80, or
Grub drive hd0. This is because what ever hard drive you boot from
is automatically set to BIOS drive 80. This is also true when you
tell the BIOS to boot from the second hard drive in the machine.

The other reason affects the kernel ordering. How the kernel assigns
drives depends on the module loading order. Because you have to load
the usb_storage module from the initrd, the USB drive is the first
controller scanned. (There are ways to change that, but it not
easy.) This affects any kernel, or distribution that uses modules.
You run into the same thing when you install Ubuntu to a USB drive.
That is why a USB install is only offered as an expert install.
Mikkel
------------------
ikkel,
thanks for response. As is often the case, your response if full of info.
I am trying to absorb it all.
> To tell if Ubuntu does the same thing, you would have to do the same
> type of install.
First, let's be sure we are on same page.
What I did was to boot a usbexternaldisk copy of main fc5.
(this was not an anaconda install to the usbdisk)
I did this 2ways, each with its own grub.conf stanza
1) using  kernel,initrd from a kubuntu 6.06 dapper
   this boots, disks are _not_ reordered   ie usb is seen as sdc
2) using the kernel,initrd of the fc5copy(same as in mainfc5)
   this boots, disks _are_ reordered   ie usb is seen as sda

But, my bios does not see the usb disk, so in _both_ cases
 I copied the /boot files from the fc5copy into  sdb3 = (hd1,2)
This makes it  some kind of usb/scsi hybrid  bc the /boot files are on sdb

So when you say "have to do same type of install"
I think you mean, make a usbdisk copy of the kubuntu install (now on sdb5)
and then use the kubuntu kernel,initrd to boot this.
Then, if this again results in disks _not_ reordered,
only then will be able to see "if ubuntu does the same thing".
Correct me if I am not understanding you.

this will take some time, but I want to go thru with it.
I first have to mv the fc5copy out of the topdir of the usb(its one large partn)
and have my backup scripts do the copy of the kubuntu install to
topdir of usb.

Jack




[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]