[svlug] "dd" first CD image to USB pendrive for booting?

[Bill-Schoolcraft]

At Mon, 11 Dec 2006 it looks like Seth David Schoen composed:

> Bill-Schoolcraft writes:
> 
> > Hello Family,
> > 
> > On various flavors of Linux, there is NFS install option(s), on
> > CentOS/RHEL* it consists of the boot arg of:
> > 
> > 	linux text askmethod
> > 
> > And when I use SuSE it consists of using their "mini-network" iso image.
> > 
> > I purchased two SandDisk 1-gig "Cruzer" drives this weekend and they
> > came with a fat32 filesystem and my objective is just to have the USB
> > pendrive "act" (or become) the first iso install image of the above
> > examples.
> > 
> > I have tried a few things on a server that works fine with a standard
> > USB_CDROM and have received "No operating system found..." etc.
> > 
> > What I have tried is the following:
> > 
> > (A) dd'd the first iso right on top of /dev/sda (the pendrive). That
> > idea came from the days of dd'ing a floopy image on top of /dev/fd0
> > 
> > (B) created /dev/sda1 on the pendrive, dd'd the image there, made it
> > bootable and nada...
> 
> Hi Bill,
> 
> Historically the boot methods for hard drive-like devices (including USB
> drives) are different from the boot methods for CD-like devices (including
> DVDs).  Hard-drive-like devices normally boot from a boot sector right
> at the beginning of the disk, whereas CDs (on PCs) normally use the El
> Torito standard.
> 
> http://en.wikipedia.org/wiki/El_Torito_%28CD-ROM_standard%29
> 
> Hard drive boot sectors and El Torito are not compatible, so you
> normally can't copy bootable ISO images onto hard drives (or vice
> versa).  This is extremely annoying.  You didn't do anything wrong,
> it's just that the BIOS is looking for a different kind of boot
> image depending on what physical medium you're booting from!  One
> of the most obvious distinctions is that the El Torito emulation
> images, unlike hard drive boot sectors, don't start at the first byte
> of the boot device.
> 
> You might be able to use LILO or GRUB to boot a kernel from the USB
> drive and then tell it to mount an ISO9660 filesystem from that same
> drive as the root filesystem.  In LNX-BBC, there was an experimental
> USB pen drive version (note: different from the regular ISO9660
> version because of the difference in boot sector formats I mentioned
> above!); if you can get the code from Paul Gray or Nate Riffe, it
> might give you some hints about how to go about adapting a CD boot
> disk to run from a USB drive.  It's possible that code will have to
> be modified in several places (for example, the list of devices that
> the initial RAM disk, if any, uses to search for the root filesystem
> to mount).
> 
> It's extremely annoying that people have to go through this rigamarole.
> I hear that the boot environments on non-PC systems (for example,
> using Open Firmware) are a little bit more sane and consistent across
> different types of boot media.
> 
> 

Thanks Seth for the quick reply -- I've actually stumbled onto
something, that if not anything else, is adding to my education about
this at:

http://fedora.redhat.com/docs/fedora-install-guide-en/fc5/ch-beginninginstallation.html#sn-booting-from-disc

Gawd, it seemed so simply in my (simple) mind when I bought these two
SanDisk "Cruzer" 1-gig USB drives.  They were on sale for $19.99 with
"no" mail-in rebates or nothing from Best_Buy.  Perfect "stormy-weather"
geek toys to play with... Little did I realize... :)

Good to hear from ya too.  Been a while since we sat next to each other
as newly hired co-workers at Linuxcare!


-- 
  Bill Schoolcraft <*> http://wiliweld.com

"Health nuts are going to feel stupid someday,
    lying in hospitals dying of nothing."
                -- Redd Foxx