how does network install figure out 64-bit from 32-bit?

Wed Aug 15 22:41:08 UTC 2007

----- Original Message ----
From: Rick Stevens <rstevens at internap.com>
To: For users of Fedora <fedora-list at redhat.com>
Sent: Wednesday, August 15, 2007 4:56:04 PM
Subject: Re: how does network install figure out 64-bit from 32-bit?

On Wed, 2007-08-15 at 13:08 -0700, Globe Trotter wrote:
> 
> ----- Original Message ----
> From: Rick Stevens <rstevens at internap.com>
> To: For users of Fedora <fedora-list at redhat.com>
> Sent: Wednesday, August 15, 2007 2:52:44 PM
> Subject: Re: how does network install figure out 64-bit from 32-bit?
> 
> On Tue, 2007-08-14 at 22:18 -0700, Globe Trotter wrote:
> > Hmmm....
> > 
> > 
> > > > Assuming the FLASH is /dev/sdb and the ISO is mounted at /media/cdrom,
> > > > then:
> > > > 
> > > >     dd if=/media/cdrom/images/diskboot.img of=/dev/sdb bs=512
> > > > 
> > > > Note the "of=/dev/sdb".  You MUST write to the raw device (/dev/sdb),
> > > > NOT to the first partition (/dev/sdb1).
> > > > 
> > > > 
> > > > 
> > > > Hi Rick,
> > > > 
> > > > Thanks very much for the detailed explanation. I have been using Linux and
> > > hence the dd command. I have done as you suggested here. But, I now get a
> > > boot error, which indicates that it is recognized as a boot device, but there
> > > is clearly an error.
> > > > 
> > > > So this is what I am doing: Pop the USB flash drive in. Look at nautilus
> > > and note that it would get mounted on /dev/sdb1 (except I have not mounted
> > > it). So, then I use the command above, and yank it out. Is this the right
> > > thing to do?
> > > 
> > > If you see it in Nautilus, it's being mounted.  
> > 
> > But I don't see it as mounted in nautilus. Just that it is there. Indeed, I
> > make sure it is not mounted. 
> > 
> > You need to close the
> > > Nautilus window first, then right click on the icon in your desktop for
> > > the FLASH device and "Unmount volume" (or run "umount /dev/sdb1" in a
> > > terminal as root).  Do NOT unplug the FLASH device or it'll mount again.
> > > 
> > > Now, with the device unmounted, do the "dd" command, but specify
> > > "of=/dev/sdb", NOT "of=/dev/sdb1" in the "dd" command.
> > > 
> > 
> > I have done exactly the same thing. Just to clarify the following is the file I
> > am copying:
> > 
> > wget -c
> > http://mirror.anl.gov/pub/fedora/linux/releases/7/Fedora/x86_64/os/images/diskboot.img
> > 
> > And then I use the dd command:
> > 
> > dd if=/media/dvd/images/diskboot.img  of=/dev/sdb bs=512
> > 
> > but to no avail. Is it possible that I am making a mess somewhere? Is it that
> > bs has to be something else?
> > 
> > Note that I do potentially get a bootable USB since it says boot error, rather
> > than OS not found.
> 
> Oh!  Then you're burning the FLASH correctly.  Are you sure this is a
> 64-bit system?  You've downloaded the 64-bit version of the image and it
> won't boot on a 32-bit system.  Try it again, but use
> 
> http://mirror.anl.gov/pub/fedora/linux/releases/7/Fedora/i386/os/images/diskboot.img
> 
> and try it.
> 
> 
> 
> 
> Hi Rick,
> 
> Thanks! On the off-chance, I tried the same thing last night and right now. But I get the same error. Btw, it appears the the file diskboot.img is the same whether it is in i386 or x86_64 but I specifically used the two links separately. 
> 
> Btw, I have looked at the image file later (after mounting on nautilus) as a file system: the stuff is all there as should be.
> 
> I am very confused. The OS I am copying this on is 32-bit but the machine (thinkpad t61) I am trying to set this on is 64-bit and the BIOS has a 64 number which would seem to suggest that.
> 
> Any other suggestions? Many thanks again for putting up with my desire to understand the process.

You know, I just tinkered with my laptop and a FLASH and it worked as
advertised.  However, I found the "+" you had on the HDD stuff in the
BIOS.  If you press ENTER when that's highlighted, it should show you
both your real hard drive AND the USB disk.  You want the USB disk to be
the first in that list.  On my HP, you use scroll down to the USB disk
and use F6 to move it up the list.

Literally, here's what I did:

1. Took an 8GB FLASH drive and plugged it into the USB port of my
desktop.  It showed up as /dev/sdc.

2. Mounted up an ISO image of F7-i386 as "/media/cdrom":

    mount -t iso9660 -o loop \
        /media/IMAGES/F-7-i386-DVD.iso /media/cdrom

3. Went into that directory's "images" directory:

    cd /media/cdrom/images

4. Did the "dd":

    dd if=diskboot.img of=/dev/sdc bs=512

5. Unplugged the FLASH from the desktop and plugged it into the laptop.

6. Powered up the laptop, went into BIOS, played with the boot order
(made HDD first, then made the USB disk first in that sublist), and
booted.  Voila!

Thanks, I did exactly the same thing, and it does say "Boot error" which means that the disk itself is being recgnized as something to boot from. Is it possible that the flash itself is the problem? Or are there some USB ports that are different from others? Though the last probably does not make sense, given that the USB SanDisk etc shows up as a bootable option under the +USB HDD: in fact, entering that gives it the only option.

Btw, this is a SanDisk Cruiser Micro 1.0 GB SDCZ6-1024 for whatever it is worth....

Btw, a  different question: how do you know that that pops up as /dev/sdc for you in the blind world of Fedora? I have assumed that it does for me as /dev/sdb because if I were to mount it using nautilus, it shows up as /dev/sdb1.

Best wishes,
Trotter

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