Exercise 34.5: Recovering Using the Install Image on Debian/Ubuntu

albiurs

Hi,

I'm sorry if I ask even one more question again. But Exercise 34.5 is only explaining the recovery of the packet on RedHat-based systems. Unfortunately I was not able to transfer the commands to Ubuntu and recover the Package from the according image. I can mount the Ubuntu install media in the rescue environment, but cannot find the requested zsh package:
alu@ubuntu-dt-vm:~$ find /media/ -name 'zsh'
alu@ubuntu-dt-vm:~$

What I found is:
alu@ubuntu-dt-vm:/media/alu/Ubuntu 24.04.1 LTS amd64/dists/noble/main/binary-amd64$ ls -lh
total 52K
-r--r--r-- 1 alu alu 52K Aug 27 18:22 Packages.gz

Which I guess is only a reference file or something?

By the way, the image is the full 6.2 GB Ubuntu Desktop 24.04 image.

Thanks,
Urs

luisviveropena

Hi Urs,

In that case you can use 'dpkg -i <package_name.deb>' with the full path, for the associated deb file you are going to install by hand. In the case of Debian, the zsh tool is available as well. The thing is that in the DVD iso for Ubuntu I can't find the zsh tool. But you can mount the iso file and search for ".deb" files, as follows:

luis@selinuxbox:~$ find /media/cdrom/ -name "*.deb"
/media/cdrom/pool/main/a/amd64-microcode/amd64-microcode_3.20231019.1ubuntu2_amd64.deb
/media/cdrom/pool/main/b/b43-fwcutter/b43-fwcutter_1%3a019-11build1_amd64.deb
/media/cdrom/pool/main/b/bcache-tools/bcache-tools_1.0.8-5build1_amd64.deb
/media/cdrom/pool/main/b/binutils/binutils_2.42-4ubuntu2_amd64.deb
/media/cdrom/pool/main/b/binutils/binutils-common_2.42-4ubuntu2_amd64.deb
/media/cdrom/pool/main/b/binutils/binutils-x86-64-linux-gnu_2.42-4ubuntu2_amd64.deb
/media/cdrom/pool/main/b/binutils/libbinutils_2.42-4ubuntu2_amd64.deb
/media/cdrom/pool/main/b/binutils/libctf0_2.42-4ubuntu2_amd64.deb
/media/cdrom/pool/main/b/binutils/libctf-nobfd0_2.42-4ubuntu2_amd64.deb
/media/cdrom/pool/main/b/binutils/libgprofng0_2.42-4ubuntu2_amd64.deb

[...]

That's on Debian 12. The thing is to find a simple package that doesn't require dependencies to install, but you can try.

Another way to make this work for Debian/Ubuntu, is to copy the zsh .deb file to the USB stick (and all its dependencies as well), so when you rescue the system, you can have the right packages to install.

Regards,
Luis.

albiurs

Hi Luis,

Thank you very much. With the Debian iso I managed it to install the according zsh packages.

In calse someone else will have to do that too, or you consider to update this course, these are the steps which I made:

1. Downloading the latest full Debian iso.
2. Booting into the Ubuntu install media.
3. Open the terminal and do as follows.

ubuntu@ubuntu:~$ lsblk
NAME                      MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
loop0                       7:0    0   1.6G  1 loop /rofs
loop1                       7:1    0   471M  1 loop 
loop2                       7:2    0 874.4M  1 loop 
loop3                       7:3    0     4K  1 loop /snap/bare/5
loop4                       7:4    0 269.8M  1 loop /snap/firefox/4793
loop5                       7:5    0  10.7M  1 loop /snap/firmware-updater/127
loop6                       7:6    0 505.1M  1 loop /snap/gnome-42-2204/176
loop7                       7:7    0  38.8M  1 loop /snap/snapd/21759
loop8                       7:8    0  74.3M  1 loop /snap/core22/1564
loop9                       7:9    0   500K  1 loop /snap/snapd-desktop-integration/178
loop10                      7:10   0 149.6M  1 loop /snap/thunderbird/507
loop11                      7:11   0 116.8M  1 loop /snap/ubuntu-desktop-bootstrap/237
loop12                      7:12   0  10.5M  1 loop /snap/snap-store/1173
loop13                      7:13   0  91.7M  1 loop /snap/gtk-common-themes/1535
sr0                        11:0    1   5.8G  0 rom  /cdrom
sr1                        11:1    1   3.7G  0 rom  
vda                       253:0    0   128G  0 disk 
├─vda1                    253:1    0     1M  0 part 
├─vda2                    253:2    0     2G  0 part 
└─vda3                    253:3    0   126G  0 part 
  └─ubuntu--vg-ubuntu--lv 252:0    0   126G  0 lvm  
ubuntu@ubuntu:~$ cd /mnt
ubuntu@ubuntu:/mnt$ sudo mkdir sr{0,1} sysimage
ubuntu@ubuntu:/mnt$ ls
sr0  sr1  sysimage
ubuntu@ubuntu:/mnt$ sudo su
root@ubuntu:/mnt# mount /dev/sr0 /mnt/sr0
mount: /mnt/sr0: WARNING: source write-protected, mounted read-only.
root@ubuntu:/mnt# mount /dev/sr1 /mnt/sr1
mount: /mnt/sr1: WARNING: source write-protected, mounted read-only.
root@ubuntu:/mnt# vgscan
  Found volume group "ubuntu-vg" using metadata type lvm2
root@ubuntu:/mnt# vgchange -ay
  1 logical volume(s) in volume group "ubuntu-vg" now active
root@ubuntu:/mnt# lvs
  LV        VG        Attr       LSize    Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  ubuntu-lv ubuntu-vg -wi-a----- <126.00g                                                    
root@ubuntu:/mnt# lvdisplay 
  --- Logical volume ---
  LV Path                /dev/ubuntu-vg/ubuntu-lv
  LV Name                ubuntu-lv
  VG Name                ubuntu-vg
  LV UUID                w50odd-lx32-TSbE-KtHx-tXiO-5nzY-DBx7iB
  LV Write Access        read/write
  LV Creation host, time ubuntu, 2024-10-29 07:36:06 +0000
  LV Status              available
  # open                 0
  LV Size                <126.00 GiB
  Current LE             32255
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           252:0

root@ubuntu:/mnt# mount /dev/ubuntu-vg/ubuntu-lv /mnt/sysimage/
root@ubuntu:/mnt# ls
sr0  sr1  sysimage
root@ubuntu:/mnt# cd sr1
root@ubuntu:/mnt/sr1# ls
boot    dists  firmware     isolinux    pool                 README.mirrors.txt
css     doc    install      md5sum.txt  README.html          README.source
debian  EFI    install.amd  pics        README.mirrors.html  README.txt
root@ubuntu:/mnt/sr1# find . -name '*zsh*'
./pool/main/z/zsh
./pool/main/z/zsh/zsh_5.9-4+b5_amd64.deb
./pool/main/z/zsh/zsh-common_5.9-4_all.deb
root@ubuntu:/mnt/sr1# dpkg --root=/mnt/sysimage/ --install /mnt/sr1/pool/main/z/zsh*.deb
dpkg: error: cannot access archive '/mnt/sr1/pool/main/z/zsh*.deb': No such file or directory
root@ubuntu:/mnt/sr1# dpkg --root=/mnt/sysimage/ --install /mnt/sr1/pool/main/z/zsh/zsh*.deb
Selecting previously unselected package zsh.
(Reading database ... 211566 files and directories currently installed.)
Preparing to unpack .../z/zsh/zsh_5.9-4+b5_amd64.deb ...
Unpacking zsh (5.9-4+b5) ...
Selecting previously unselected package zsh-common.
Preparing to unpack .../z/zsh/zsh-common_5.9-4_all.deb ...
Unpacking zsh-common (5.9-4) ...
Setting up zsh-common (5.9-4) ...
Setting up zsh (5.9-4+b5) ...
Processing triggers for debianutils (5.17build1) ...
Processing triggers for man-db (2.12.0-4build2) ...
root@ubuntu:/mnt/sr1#

4. Remove the Ubuntu install media and reboot the system.

Thanks again, Luis!

Best wishes,
Urs

luisviveropena

Hi Urs, it's a pleasure! I'm glad you were able to do it on Ubuntu/Debian.

Regards,
Luis.