How to make a live CD/DVD from your harddisk installation

[capink]

Hi, Thanks for the great guide capink!

I was curious though would it be possible to use lzma compression for mksquashfs. I think it would be a great way to fit a little extra on a cd. I am not sure exactly how to rebuild the kernel with support for reading from an archive compressed with lzma. I would guess you would have to use the package "lzma-source", but beyond that I'm not sure what to do. I think it would be great to get working on many systems that are just barely too big for a CD. The closest I've come so far is finding the pre-built kernel from "http://www.squashfs-lzma.org/", however I've found hardware support to be insufficient for my system. Is there a way to get the hardware support of Ubuntu while getting the better compression ratios as well?

If that doesn't work, is there any other way to get a better compression ratio?

Thanks

I have not looked at lzma yet. But in debian lenny which I am currently using, there is lzma-modules-$(uname -r). So you might want to install the debian kernel in Ubuntu and see how it works. But I cannot guarntee it will work.

Note that you have to install the following packages from Debian repositories together:

sudo apt-get install linux-image-$(uname -r) squashfs-modules-$(uname -r) unionfs-modules-$(uname -r) lzma-modules-$(uname -r)

where $(uname -r) is the kernel version.


Or if you do not mind it, you can switch to Debian.

[bkrsml]

I will be reposting this message as a reply to the top level post. I am only doing this because I accidently replied to the wrong thread.

I agree with the others that this is a very well written how-to.

I tried a subset of the instructions for a different but related goal. The results were not quite what I was looking for but I still think these instructions are close.

I know I was taking a lot of liberties with my subset of the instructions but I am hoping someone can help me with this or at least point me in the right direction.

Below are the details of my goal, the steps I used to try to reach it, and the results. Thanks in advance for any help.

GOAL:
I have an SDHC card (High Capacity SD card) on a USB reader. The card has a physical write protect switch which is an important reason I am using it. I want to be able to run Ubuntu from the card like it was a regular drive and to run it when the card is write locked. This thread caught my attention because I would like the write locked sessions to use the same image as the read-write mode. I do not mind having to perform some simple steps from the read-write boot every time I want to update the write-protected image.

ACTIONS:
I installed from the 8.04.1 desktop CD and that worked fine. I installed a package, a printer, and did other configuration. Then to support the write locked boot I did the following:

1. Updated Packages

2. I issued the last command of C.1
LANG=

3. Changed the initial users uid to 500 to get it under 1000
sudo usermod -u 500 <username>

4. Installed casper discover1 xresprobe
I would like the write-locked boot to use the GDM configuration from the install because my driver and resolution are not detected correctly by the 8.04.1 LiveCD on the system I am using to build and test this card. However I would also like the card to be portable across a wide number of machines and be able to detect settings (for both read/write and write-locked boots).

5. I then did step C.4
sudo depmod -a $(uname -r)
sudo update-initramfs -u -k $(uname -r)

6. I did not do step C.5. I ran this step on a previous attempt and it created problems. I think this is because I am running from the same system I am modifying (no chroot). I did not do steps C.6 and C.7 because space is not too much of an issue at this point.

7. I did not do step C.8 because I was hoping the user id change mentioned in my step 3) above would take care of the issue.

8. I did not do step C.9 again because space was not an issue.

9. I did not do step C.10 because I was hoping to use the GDM configuration from my read-write install.

10. I did not do step C.11 again because space was not an issue.

11. I modified /boot/grub/menu.lst
I added an entry by coping the default that was already there. I added boot=casper and nopersistent
title Read Only Ubuntu 8.04.1, kernel 2.6.24-19-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.24-19-generic root=UUID=<ID> BOOT=casper boot=casper nopersistent rw quiet splash
initrd /boot/initrd.img-2.6.24-19-generic
quiet

RESULTS:
If I choose the installed read-write default option from the grub menu everything seems to perform just as before.

If I choose the new "Read Only" option I seem to get pretty much an uncustom LiveCD image. I was automatically logged in to the Live Session User, my driver and resolution were incorrectly detected, the user I created on install is not available, a printer I had registered was not available, and a package I had loaded was not found (however casper, discover1, and xresprobe were installed according to Synaptic).

[adamogardner]

cli - tech difficulties. making bootable dvd

ok so I am following the steps. I was converting the directory tree into a squashfs and it just ceased:

adamogardner@CRONUS:~$ sudo mksquashfs ${WORK}/rootfs ${CD}/${FS_DIR}/filesystem.${FORMAT}
sudo: unable to resolve host CRONUS
Parallel mksquashfs: Using 2 processors
Creating little endian 3.1 filesystem on //filesystem., block size 131072.
[============================ ] 73842/149545 49%

so I opened a new tab and tried it again but to no avail:

adamogardner@CRONUS:~$ sudo mksquashfs ${WORK}/rootfs ${CD}/${FS_DIR}/filesystem.${FORMAT}
sudo: unable to resolve host CRONUS
Can't find a SQUASHFS superblock on //filesystem.
Failed to read existing filesystem - will not overwrite - ABORTING!
To force Mksquashfs to write to this block device or file use -noappend
adamogardner@CRONUS:~$

Is my disk too small? how can I tell? What can I do?

[bab1]

adamogardner@CRONUS:~$ sudo mksquashfs ${WORK}/rootfs ${CD}/${FS_DIR}/filesystem.${FORMAT}
sudo: unable to resolve host CRONUS

This appears to be a DNS problem with your setup. Not the LiveCD setup. Check to see if your hostname is resolved correctly.

[Oldsoldier2003]

This appears to be a DNS problem with your setup. Not the LiveCD setup. Check to see if your hostname is resolved correctly.

Yes its a problem with sudo resolving the host. It happens a lot with upgraded installations since gutsy.
To the OP:
Make sure the hostname in /etc/hosts matches the name in /etc/hostname , also be aware that if your hostname file or hosts file list your computer as hostname.somedomain sudo will fail. To fix it launch a text editor and remove the suffix (.somedomain). (Don't forget that you need to edit these files as superuser:

sudo nano /etc/hosts

[bkrsml]

This is was originally posted as a reply to a sub-thread. I am now trying to post it as a reply to the top level post. Sorry for the duplicate.

I agree with the others that this is a very well written how-to.

I tried a subset of the instructions for a different but related goal. The results were not quite what I was looking for but I still think these instructions are close.

I know I was taking a lot of liberties with my subset of the instructions but I am hoping someone can help me with this or at least point me in the right direction.

Below are the details of my goal, the steps I used to try to reach it, and the results. Thanks in advance for any help.

GOAL:
I have an SDHC card (High Capacity SD card) on a USB reader. The card has a physical write protect switch which is an important reason I am using it. I want to be able to run Ubuntu from the card like it was a regular drive and to run it when the card is write locked. This thread caught my attention because I would like the write locked sessions to use the same image as the read-write mode. I do not mind having to perform some simple steps from the read-write boot every time I want to update the write-protected image.

ACTIONS:
I installed from the 8.04.1 desktop CD and that worked fine. I installed a package, a printer, and did other configuration. Then to support the write locked boot I did the following:

1. Updated Packages

2. I issued the last command of C.1
LANG=

3. Changed the initial users uid to 500 to get it under 1000
sudo usermod -u 500 <username>

4. Installed casper discover1 xresprobe
I would like the write-locked boot to use the GDM configuration from the install because my driver and resolution are not detected correctly by the 8.04.1 LiveCD on the system I am using to build and test this card. However I would also like the card to be portable across a wide number of machines and be able to detect settings (for both read/write and write-locked boots).

5. I then did step C.4
sudo depmod -a $(uname -r)
sudo update-initramfs -u -k $(uname -r)

6. I did not do step C.5. I ran this step on a previous attempt and it created problems. I think this is because I am running from the same system I am modifying (no chroot). I did not do steps C.6 and C.7 because space is not too much of an issue at this point.

7. I did not do step C.8 because I was hoping the user id change mentioned in my step 3) above would take care of the issue.

8. I did not do step C.9 again because space was not an issue.

9. I did not do step C.10 because I was hoping to use the GDM configuration from my read-write install.

10. I did not do step C.11 again because space was not an issue.

11. I modified /boot/grub/menu.lst
I added an entry by coping the default that was already there. I added boot=casper and nopersistent
title Read Only Ubuntu 8.04.1, kernel 2.6.24-19-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.24-19-generic root=UUID=<ID> BOOT=casper boot=casper nopersistent rw quiet splash
initrd /boot/initrd.img-2.6.24-19-generic
quiet

RESULTS:
If I choose the installed read-write default option from the grub menu everything seems to perform just as before.

If I choose the new "Read Only" option I seem to get pretty much an uncustom LiveCD image. I was automatically logged in to the Live Session User, my driver and resolution were incorrectly detected, the user I created on install is not available, a printer I had registered was not available, and a package I had loaded was not found (however casper, discover1, and xresprobe were installed according to Synaptic).

[capink]

GOAL:
I have an SDHC card (High Capacity SD card) on a USB reader. The card has a physical write protect switch which is an important reason I am using it. I want to be able to run Ubuntu from the card like it was a regular drive and to run it when the card is write locked. This thread caught my attention because I would like the write locked sessions to use the same image as the read-write mode. I do not mind having to perform some simple steps from the read-write boot every time I want to update the write-protected image.

If I understood what you want to do properly, this link might help you achieve what you want. The method outlined there uses live-initramfs instead of casper. Keep in mind that people had a mixed results using this method depending on their hardware as well as the size of the image they are creating.

[bkrsml]

Thanks capink. I looked at the link and it appears that it might get me what I want. I am also going take a closer look at initramfs, live-initramfs, and casper. I think I need to understand them at a lower level.

[Rurushu]

Thanks for the tutorial... It is really helpful

I have few questions, if that possible...

1. When I reboot my LiveCD, everything goes well.. grub starts, I choose an option, ubuntu loading, and then BusyBox shell starts instead of loading the system...

I tried cat casper.log

(initramfs) cat casper.log
/init: /init: 1: cannot open /dev/fd0: No such device or address
stdin: error 0
/init: /init: 1: cannot open /dev/fd0: No such device or address
stdin: error 0
/init: /init: 1: cannot open /dev/fd0: No such device or address
stdin: error 0
/init: /init: 1: cannot open /dev/fd0: No such device or address
stdin: error 0
Unable to find a medium containing a live file system

[EDIT]: ISSUE 1 SOLVED...

2. If I created a new filesystem, manifest, manifest-desktop and md5sum.text files... then replaced the files in ubuntu live cd with the new files... well that be enough? If no, why?!

Thanks alot

[karika200]

In debian lenny repositories I can't found the unionfs modul for the precompiled(2.6.25) kernel, but there is a package aufs. I installed aufs, but at boot, it requires unionfs. What should I do?:\