How do I back up the list of applications I have installed?

Solution 1:

Check out AptOnCD (aptoncd ).

sudo apt-get install aptoncd

Solution 2:

Yes, aptonCD will do that, If you want to backup them manually, just copy the /var/cache/ap/archives directory.And in the new system, Just copy the backed up cache and overwrite the same directory with root permissions, use synaptic to install those (But you will have to install dependencies manually) But if you have deleted the cache recently, you won't get them!.If you have windows intalled and use a wubi installation, just backup the wubi root file elsewhere. I think that's the best method to backup your system and make experiments on ubuntu!

Solution 3:

                                                      Thats is very simple & easy task

          1. create a tar /var/cache/apt/archives

 tar cvf archives.tar /var/cache/apt/archives

          2. now backup archives.tar

          3. Now Install Ubuntu

          4. After Installing Ubuntu check for updates & close it

          5. now extract archives.tar at /var/cache/apt/

sudo tar xvf archives.tar /var/cache/apt/

          6. i did a reboot ( Dont know may be Optional )

          7. Now check for Updates they will 0 MB to Download OR may be some kb's

                                        Verified & Checked on 1 host OS & 5 VM's

                                                            A GUI based solution

sudo nautilus

          make a tar & then backup

          Install Ubuntu & Check for Update & Close it

          after that again open terminal & sudo nautilus

          open archieve.tar & Drag Drop it As shown in pic

          & then again Check for Update , it will be 0 MB

Update Alternative for Ubuntu