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View Full Version : [SOLVED] 10.10 on LiveUSB: Possible to boot from a subdir?



gringo guy
November 29th, 2010, 05:58 AM
Hi all. . . I'm fairly new to Ubuntu, but have been around Unix/Linux for ages. Earlier this year I spent some time to get 9.10 booting from a LiveUSB stick. It worked great, everything just as I'd hoped, but ran out of time to pursue it.

So, now I'd really like to build a LiveUSB with 10.10, in the same environment that was working so well earlier. That means 10.10 in a subdirectory on the USB stick so it will co-exist with other Live Distros, and also boot on my Macbook.

With 10.10 in the root of the USB, everything works perfectly. However, as soon as I move Ubuntu down into a subdirectory and modify the /syslinux/txt.cfg file, it boots part way, dumps me into a BusyBox shell, and fails with the following error message.


(initramfs) Unable to find a medium containing a live file systemI've searched here and elsewhere, but haven't found the answer yet. Here's the syslinux entry from the modified txt.cfg file. This is similar to the entry that works great with 9.10, but that did not have the 'preseed file' entry and did not use persistence.



kernel /ubuntu/casper/vmlinuz
append noprompt cdrom-detect/try-usb=true file=/cdrom/preseed/ubuntu.seed boot=casper persistent initrd=/ubuntu/casper/initrd.lz splash --Both vmlinuz and initrd.lz load, I get the splash screen, then the LED on the USB flashes for a while (but less than a minute), and then gives the above msg. The only changes made to the above was prefixing with the /ubuntu subdirectory. (I also tried adding the subdirectory prefix to the preseed file, but that didn't work either.)

What other info would help? I'm using the 32-bit Desktop Ubuntu on an older Gateway with AMD cpu. I used the PendriveLinux Universal USB Installer v1.8.1.5 downloaded today to do the initial Live setup in USB's root dir.

I hope this is possible. Any suggestions?
Thanks!

prshah
November 29th, 2010, 06:26 AM
10.10 in a subdirectory on the USB stick so it will co-exist with other Live Distros,

Hi, I have built a multi-boot DVD using Grub4DOS, after trying many unsuccessful changes to the preseed and other files.

Using Grub4DOS, you can boot an ISO image of the linux distro of your choice. You can get the details from the link in my sig, below.

oldfred
November 29th, 2010, 06:35 AM
Somewhat like the grub4dos versions, but using grub2. If you have a 8GB or larger flash you can do a full Ubuntu install. I have several ISO installed on my 4GB flash drive using grub2.

MultiBootUSB - Install and boot multiple Linux from Pendrive / Flash drive / USB disk
http://ubuntuforums.org/showthread.php?t=1518273
multicd.sh - combine Linux ISOS into one
http://ubuntuforums.org/showthread.php?t=1071869

HOWTO: Booting LiveCD ISOs from USB flash drive with Grub2
HardDrive
http://ubuntuforums.org/showthread.php?t=1549847
http://ubuntuforums.org/showthread.php?t=1288604
Basically you just install grub2, create a folder for the isos and edit a grub.cfg to loop mount the isos.
http://ubuntu-ky.ubuntuforums.org/showthread.php?t=1535864

C.S.Cameron
November 29th, 2010, 07:22 AM
I will vouch for Oldfred's first option, MultiBootUSB.
But you need to run it from a Linux invironment.

gringo guy
November 29th, 2010, 07:57 AM
prshah: interesting you mention grub4dos. I was looking at the MultiBoot USB (http://www.pendrivelinux.com/boot-multiple-iso-from-usb-multiboot-usb/) tool from Pendrivelinux earlier to day, but from the description it sounded like it was unpacking the ISOs each time you booted. Guess I'll have to look into this further.

oldfred, and c.s.cameron: thanks for confirming. . . I need to take another look at the various MultiBoot tools. Either that or just install directly to the USB. From other posts here, sounds like flash sticks don't wear out as fast as some people had thought earlier. Question: Do you see longer boot times when booting from an ISO file?

Looks like there are three MultiBoot tools, two for Linux (the one you mention and MultiSystem (http://www.pendrivelinux.com/multiboot-create-a-multiboot-usb-from-linux/) from Pendrivelinux, and one for ******* (the one above, from Pendrivelinux). Many choices. Thanks, guys!

Oh the other hand, I spent quite a bit of time building syslinux menus for a distro that had dozens and dozens of text-menu files (found a nice template here (http://blog.mycila.com/2010/01/backtrack-with-ubuntu-usb-key.html)), and wouldn't look forward to redoing all of those! However, I do see that it's possible to do graphical menus (http://sites.google.com/site/rmprepusb/tutorials/grub4dos) and create submenus, so they could be redone. I was sorta' hoping for a simple syslinux solution.

This will take some rethinking, but I'll let you know what works, when it does.

C.S.Cameron
November 30th, 2010, 03:37 AM
From other posts here, sounds like flash sticks don't wear out as fast as some people had thought earlier.

I have actively tried to find someone in these forums who has actually worn out a flash drive running Ubuntu from it, without success.

Most flash drives are good for at least 10000 writes and have wear leveling, (and unlimited reads).
Figure 10000 x 16000000000 Bytes @ 5000000 Byte/sec write speed = 1111 8 hour days.

I don't think using a .squashfs file in itself makes for noticeably longer boots.

gringo guy
January 15th, 2011, 05:14 AM
Hi again. . . been distracted for a while, switching full time to Ubuntu. No more Windows, Yay! This is really fantastic.

Anyway, finally got back to trying this. Thanks again oldfred and c.s.cameron. The MultiBootUSB.sh script by Ramesh & Sundar works great. It is very nice to both see what the script is doing, and to easily make some changes (as opposed to a Windows .exe method).
Salud!