Replace boot floppy with USB stick

[JClosed]

I have been looking for an answer, but not find any searching the web. So - I hope there are some people here that can help me.

I going to re-install Fedora 14 and several other OS-es on a multi boot system.

Now - my normal procedure is to install fedora 14 last and use the grub boot loader to load the other OS. As I use a hard disk to regularly install an experimental OS I keep my grub boot on a back-up floppy. The installation is done (as root) in this way:

modprobe floppy
fdformat /dev/fd0
mke2fs /dev/fd0
mount -t ext2 /dev/fd0 /mnt/floppy
grub-install --root-directory=/mnt/floppy '(fd0)'
cp /boot/grub/grub.conf /mnt/floppy/boot/grub/grub.conf
umount /mnt/floppy

This works great. If your mbr is overwritten by another OS you can use the boot floppy to get into Fedora - no problem.

However - my new system has no longer a floppy disk drive (no connection the motherboard). I wonder if can use a USB stick in stead of a floppy to boot Fedora if my mbr is overwritten. I only have no clue how to do that. The above procedure can obviously not be used, because a stick is no floppy.

Can anyone give me the good procedure to do this. Please notice - I am NOT asking for a full Fedora on the stick!!! I only want t use the stick to boot my hard drive based Fedora if the mbr is overwritten.

Thanks in advance.

[JEO]

There is a drive you can buy called an external usb floppy drive, so that's one idea.

The other idea is that you could do the same thing with a usb flash drive if you are willing to reformat it as ext2 (or 3 or 4) like you did the floppy disk. Most motherboard BIOSes will boot a usb flash drive if it has a partition table on it and and active primary partition. Most USB flash drives come formatted with a partition table and one primary fat or fat32 partition.

[JClosed]

That was what I was trying to do. I formatted the USB stick as ext2. Then mounted the stick just like I did with the floppy.

However - when I tried the to install grub using grub-install I get:

Probing devices to guess BIOS drives. This may take a long time.
Format of install_device not recognized.

And then the install stopped. I tried to write something on the USB stick and that works without a problem. The stick is recognised as a ext2 file device, and it has the boot flag set. I have no idea why the grub-install command says it cannot recognise the format of the install device (USB stick) because it's format is clearly ext2.

[JEO]

Could it be that you formatted it as a single ext2 volume without using a partition table?

An example would be

mkfs.ext2 /dev/sdc

That would probably give grub-install grief because there is no partition table or master boot record.

An example of formatting it using a partition table:

mkfs.ext2 /dev/sdc1

Of course if you don't have a partition table you would need to create one using gparted or whatever first.

---------- Post added at 02:57 PM ---------- Previous post was at 02:52 PM ----------

I would try it without using the grub-install script:

Example
Lets say the usb stick is at /dev/sdc

Invoke the grub shell

su -
grub --device-map=/dev/null
device (hd0) /dev/sdc
root (hd0,0)
setup (hd0)

(because I use dmraid the grub-install script fails so often that I never use it anymore)

[SiliconSlick]

Assuming you don't care about the data on the USB Flash key, you can try something like:

mkbootdisk --device /dev/sdX --size 20000 `uname -r`

where /dev/sdX is your USB key (BE CAREFUL!). (--size is a rough estimate which works with the latest i686 FC14 kernel here... adjust as needed)

That seems to work here. Although I didn't actually wax my MBR to test it, if I edit the syslinux.cfg that is created on the USB key and removed 'rhgb quiet' then I get a gloriously verbose bootup with all the gory details (which might be useful if you have waxed your HD MBR and there are problems), which is not my standard bootup on my HD (so I know it is booting from there USB in my testing).

Be sure to use an old/small (approx. 20MB in this example) Flash since, as a floppy, it doesn't have a partition table (AFAICT). The --iso option of mkbootdisk might make it possible to use the rest of the drive I but haven't tested it. If you do, let us know how it goes (and/or if it works at all).

SS

[stoat]

Originally Posted by JClosed

This works great. If your mbr is overwritten by another OS you can use the boot floppy to get into Fedora - no problem.

Some other ideas to consider for that when there is no floppy drive...

If another system's GRUB gets written into the MBR, you can boot it, stop its GRUB at the boot menu, press "c" to get the GRUB shell prompt (grub>), then boot Fedora with simple GRUB shell commands. Even the GRUB 2 boot menus still do that. Once Fedora is running, it's another simple matter to re-install its GRUB boot loader with grub-install or the usual GRUB shell commands.

Make a GRUB boot CD to boot the machine to a grub> prompt and boot Fedora with GRUB shell commands. Or, you can add Fedora's grub.conf file to the project to make it boot straight into the Fedora boot menu. Then re-install the GRUB boot loader.

Download and create a Super Grub Disk. Not only can its boot menu be stopped at the useful grub> prompt, the Super Grub Disk can emergency boot Linux and Windows systems (if they are still capable of being booted). It does other things, too, such as re-install GRUB and restore an "MS-like" syslinux boot loader to the MBR to make Windows boot from BIOS again. It comes in versions for Legacy GRUB, GRUB 2, floppy, CD, and USB. I think everybody using GRUB should possess one of these anyway.

[JClosed]

Thanks a lot...

I will take a look at the Super Grub Disk. Looks nice.
The command SiliconSlick gave me worked perfect. And the advise i got here gives enough alternatives to feel comfortable.

Wow - after so many years it will feel strange to have a computer without a floppy disk drive. I can remember the time the floppy was the ONLY device to boot a computer. Hard disks where way to expensive at that time. Even a floppy disk drive was not cheap at all. At that time I was using a BBC-B computer, and all programs and OS where stored in PROM's When you bought a program it was delivered on a set of ROM's, you have to install on your main board.

Times have surely changed now... ;-)