Got Knoppix 5.0.1 successfully booting from USB key

**330toSRT8** · 02-21-2007, 05:28 PM

FYI for large thumb drive users.

I used mkbootdev on a 16GB Corsair Voyager flash drive with FAT32. It booted fine on a Dell Latitude D620. I then tried it on a Dell Inspiron 9100, but it didn't work. The first screen came up where you can do boot options, but it would not take any keyboard input; appeared to be locked up.

**Godfearer22004** · 02-24-2007, 11:58 PM

Hello Everyone,
I just thought I would update everyone on my findings just in case any others could benefit. I posted a few months ago trying to get my 1GB flash drive to boot Knoppix 5.0 on my computer, but to no avail. I recently bought a new laptop, and was going to see if I would get any different results with Knoppix USB booting, but didn't get the chance for quite sometime. I actually was using the USB stick in Windows for a while and had to reboot, and was SHOCKED when suddenly Knoppix popped up onto my screen. This new computer has a USB setting called "Usb HDD" or something like that, and it worked perfectly. The only hitch I've had in the "Usb Knoppix booting" scene is making the USB flash drive writeable. I've followed the directions, but they didn't seem to help. I'd be glad to hear some advice about this subject. Also, is it possible to Update to Knoppix 5.1 rather than re-installing? Thanks for the help everyone!

**WyldOne** · 02-27-2007, 06:28 AM

Yes, you can use Knoppix 5.1. I just set uip a 1Gb drive with mkdiskimage -F -4 /dev/sdz and it worked fine.

Tested on a Dell Gx850 (sata only) no problems.

**Krellan2** · 02-27-2007, 09:23 AM

Hi again. I have done some experimentation with large USB key, and found a sequence of commands that seems to work for USB devices bigger than 8GB (such as hard disks).

I updated the article with various mkdiskimage command lines to try, depending on the size of your USB key.

Code:

mkdiskimage -4 /dev/sdz 0 64 32

This is the "easy" one, fully USB-ZIP compliant, for 1GB.
FAT16, fourth partition, 64 heads, 32 sectors.

Code:

mkdiskimage -4 /dev/sdz 0 128 32

This is for between 1GB and 2GB. It's the same thing, except the number of heads has been bumped up to 128, to double it. Still nice even numbers, though. Not USB-ZIP compliant, but I'm hoping that this is still close enough to work.

Code:

mkdiskimage -F -4 /dev/sdz 0 255 63

This is for between 2GB and 8GB. FAT16 maxes out at 2GB, so we must now use FAT32. Also setting heads and sectors to the maximum allowed values, which seems to be good enough for USB-HDD. I could squeeze in a little bit more by using 256 heads, but it seems that 255 heads is better preferred (old DOS and BIOS versions had problems "rolling over" at 256 heads).

Code:

mkdiskimage -F -4 /dev/sdz 1 255 63
dd if=/dev/zero of=/dev/sdz bs=1 seek=446 count=64
echo -e ',0\n,0\n,0\n,,C,*' | sfdisk /dev/sdz
mkdosfs /dev/sdz4

Here's the fun one! This is for bigger than 8GB. The mkdiskimage script crashes out when the number of cylinders goes beyond what could possibly fit, but I still wanted to use mkdiskimage to lay down the MBR and partition table on the disk. So, mkdiskimage is used here to make a dummy small 1MB partition. Then, the partition table is manually blanked, so that sfdisk has a clean slate to work with. The sfdisk program can correctly see the entire disk and it sizes the partition correctly. It then needs to be formatted, which mkdiskimage automatically does but sfdisk doesn't, so finally, the mkdosfs program is used to do the FAT32 format.

I tested this and it worked on a 320GB USB hard disk, which was big enough for me. This technique should be good for all devices up to 2TB in size, at which point the partition table overflows yet again (the LBA sector count is only 32 bits). Anyone tried a disk (RAID array, for now) larger than 2TB?

**MrGreen** · 02-27-2007, 09:47 AM

Which version of Knoppix did you put on 320gb drive ?..... thinking there is plenty of room for dvd version

with a couple of gig to spare lol

Got an old 80gb drive here may be able to test your huge version out ....

MrG

**Krellan2** · 02-27-2007, 11:08 AM

Originally Posted by MrGreen

Which version of Knoppix did you put on 320gb drive ?..... thinking there is plenty of room for dvd version

with a couple of gig to spare lol

I used the DVD of Knoppix 5.1.0. Had some kind of weird problem with 5.1.1 so downgraded to 5.1.0.

**MrGreen** · 02-27-2007, 01:42 PM

D/l 5.1.1 now ... will test it out see what happens

**Krellan2** · 03-01-2007, 08:22 AM

Originally Posted by 330toSRT8

What is the advantage to doing all steps mentioned in previous posts compared to just running this command?

Code:

mkbootdev

I clicked through a couple screens and then I had a bootable thumb drive.

No advantage, really. Use whatever works best for you.

The instructions here work on a few more BIOS's than mkbootdev does, since here we use FAT16 instead of FAT32 for small drives, and FAT16 is better liked by some weird BIOS's.

Also, the instructions here predate mkbootdev, which didn't exist at the time they were first made.

**MrGreen** · 03-01-2007, 08:32 AM

are you going to update your guide to include above for larger [huge!] usb drives ?

**Krellan2** · 03-01-2007, 12:45 PM

Originally Posted by MrGreen

are you going to update your guide to include above for larger [huge!] usb drives ?

Already been done.

Check the new code boxes near the mkdiskimage section.

There's now 4 boxes, each with the correct commands to use for the 4 "sizes" of drives that need to be dealt with differently:

<= 1GB (max of USB-ZIP "standard", easiest, uses FAT16)
<= 2GB (max of FAT16 filesystem, yes I know that certain versions of WinNT had a nonstandard FAT16 variation that could go up to 4GB but that is getting pedantic)
<= 8GB (max of old-style CHS addressing)
>8GB (LBA, should be good up to 2TB, uses FAT32, requires some manual fudging to get working)

I'm hoping the reader is quick enough to catch that they should use only one of the 4 boxes, based on the size of their drive, and not try all 4 commands at once