ISO Booting with Grub 2

[RobHK]

The "}" was indeed the problem. I missed it out when copying.

Parted Magic is now up and running. I can't get the Live DVD to work, but I'm not trying any more. Since it will only be needed once, I burned it to a re-recordable disc. Having PM available on tap is useful though.

Thanks again.

[karmila]

Hi drs35, great tutorial!

I tried this tutorial on my pc, since my motherboard don't have ability to boot from usb, it will save much cd's for each new install.

But i got this message when i tried to boot to iso from grub2.

Busybox v1.13.3
(initramfs) could not find the ISO /iso/ubuntu-10.10-desktop-i386.iso
This could also happen if the file system is not clean because of an operating system crash, an interrupted boot process, an improper shutdown, or unplugging of removable device without first unmounting or ejecting it
To fix this, simply reboot into Windows let it fully started, log in, run 'chkdsk /r', then gracefully shutdown and reboot back into Windows. After this you should be able to reboot again and resume the installation.

I'm sure that i have put the path correctly and tried different iso too but still got this error message. I don't have windows installed.

Is it bios related?

[ranch hand]

I, for one, are glad to here you do not have MS installed on your box.

Two questions;
Is the ISO on your / partition?
Is it owned by root?

If the answer to both is true then I have not got a clue. If the answer to either one is false then you need to fix it so it is true.

I know this for a fact as they are mistakes I made.

I use a / and a /home partition and tried to boot with the entry pointing at my root partition (OK, so I am simple).

I had left the permissions as they are normally (owned by user). This will not work as grub is looking for a root file.

To fix both of these I created /etc/aa just for ISOs. You can't put anything in there except as root, gives me an easy target to point the menu entry at.

[drs305]

An easy way to troubleshoot this (well, a not difficult way) is to go to the Grub prompt and try to 'loop' the file.

But first, from the error message, the system is looking for the file in /iso, meaning that the ISO is located in the iso file under the main folder (for example: /iso/ubuntu-10.10-desktop-i386.iso). Is that where it is?

Back to the first paragraph. At the grub prompt (press "c" from the Grub menu) and load the first part of your current linux line:

loopback loop (hdX,Y)/<path>/filename.iso

Enter the full path and ISO name.
Example:
loopback loop (hd0,5)/iso/ubuntu-10.10-desktop-i386

Repeat the procedure for the linux line. You only have to enter the line through vmlinuz before pressing ENTER.
Then do the same for the initrd line.
Watch for errors indicating an improper path or invalid or missing file name.

If you have the correct address and ENTER, nothing will happen. If you don't have the correct address, it will say "error: file not found" in which case you have to experiment with the address until you find the correct one.

And, as ranch hand notes, if it's in a separate /home folder it can cause confustion. There is a special note in the first part of the guide.

If the command above works the first time, the next thing to check is the boot= part of the linux line. (Note is is boot and not root. It should normally be "casper". You can inspect the CD's contents from the LiveCD by mounting it and opening a file browser.

If the ISO is on your Desktop:

sudo mkdir ~/Desktop/iso
sudo mount -o loop ~/Desktop/ubuntu-10.10-desktop-i386.iso ~/Desktop/iso
nautilus ~/Desktop/iso

See if the casper folder exists, and if so, that it contains the vmlinuz and initrd.lz files. Note in recent releases it is initrd.lz. Older versions were initrd.gz Make sure your initrd line matches what is contained in the casper folder.

[karmila]

I, for one, are glad to here you do not have MS installed on your box.

Two questions;
1. Is the ISO on your / partition?
2. Is it owned by root?

1. Yes, I put the iso at /boot/iso.
2. So, the answer is yes.

My ubuntu partition is at sda2, then i set this on /etc/grub.d/40_custom
menuentry "Maverick ISO" {
loopback loop (hd0,2)/boot/iso/ubuntu-10.10-desktop-i386.iso
linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=/iso/ubuntu-10.10-desktop-i386.iso noprompt noeject
initrd (loop)/casper/initrd.lz
}

I have tried another iso (Lucid) but still got the same error.

[drs305]

Edit: See oldfred's next post.

karmila,

I duplicated your entry and it worked for me. The only two things that come to mind are the filename (-i386 vs -amd64 or 10.04 vs 10.10) or a filesystem problem. You could also try moving the ISO to another location, such a / or better yet onto another partition.

Assuming the filename is correct, you might boot a LiveCD and do a filesystem check via Disk Utility or command line. You can also just set the system to do one automatically on the next boot with the following command:

sudo touch /forcefsck

[oldfred]

I think you are missing a /boot

menuentry "Maverick ISO" {
loopback loop (hd0,2)/boot/iso/ubuntu-10.10-desktop-i386.iso
linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=/boot/iso/ubuntu-10.10-desktop-i386.iso noprompt noeject
initrd (loop)/casper/initrd.lz
}


To make sure you have the same path I prefer this style using a set isofile - example from mine that worked:

menuentry "Ubuntu 10.10 Maverick ISO 64bit" {
set isofile="/boot/iso/maverick-desktop-amd64.iso"

loopback loop (hd0,2)$isofile
linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile nomodeset
initrd (loop)/casper/initrd.lz
}

[karmila]

drs305 thanks,

Here is my report:
1. I 'loop' the file with no error
My input lines are:

loopback loop (hd0,2)/boot/iso/ubuntu-10.10-desktop-i386.iso
linux (loop)/casper/vmlinuz
initrd (loop)/casper/initrd.lz

2. boot= part is fine
I mounted the iso and all necessary file are exist.

3. Still can't boot iso from grub
I once again tried boot the iso and still got the same error also when i change directory the iso to /etc/aa like ranch hand did (yes i had moved the iso to that folder and update-grub )
It produces the same error message:
...could not find the ISO /iso/ubuntu-10.10-desktop-i386.iso...
but this time with an extra line (or maybe i forgot to write it down before) after (initramfs)
(initramfs) /scripts/casper_premount/20iso_scan: line 46: Can't open /dev/sdc: No medium found.

sda= my primary HDD
sdb= my secondary HDD
sdc= should be my DVD (Not automatically mounted on start up) << Is it related?

[karmila]

Thanks oldfred... I missed that
I don't know if this is only happen to me but i copied the lines from the first post

Now, i can successfully boot the iso from grub, and it is fast!

I thank You all for helping me. drs305, ranch hand, and oldfred

Since now I can boot the iso, here is my question:
Can I do install ubuntu with this boot method at existing partition or new partition?

[oldfred]

I always thought you had to use a different partition. I know gparted will not let you edit the partition you are in. But someone claimed it worked to install over itself, but I do not believe it would work correctly.