OK, i've read the title, wtf is that ? So first i'm going to explain what i'm going to do, and why i'm doing it. When we want to try ubuntu without installing, we have two option,

1. Throw the iso into virtualbox and taste the new system.
2. Make a live usb disk and boot my computer from it.

Now i want to persist some changes, i installed some packages, created some files, i want to have them when i boot this live system again. Easy, just add some persistent space when creating the live usb. But if i want to do that in virtualbox ? What if i dont want to reboot my pc, i want do my other tasks and want to try out ubuntu in parallel ? Voila! install that ubuntu inside virtualbox. OK, but now i dont want to waste a few gigs of my disk space (not to mention the time to install ubuntu). I want to use persistance with that live system. There was no way till now

But fear not, Thats what i'm going to do now I'm gonna make a virtualbox image from ubuntu iso, adding a persistent space with it in the process.

Requirement

1. Virtualbox.
2. Unetbootin.

Procedure

I did this in mac, but pretty same process will be applicable for linux too (hopefully). Now head over to terminal and follow the steps.

1. Lets create a folder and do all the bullshitting inside it.

   $ mkdir ubuntulive
   $ cd ubuntulive
   

2. Lets make a empty 1.0GB image to hold all that bullshit.

   $ dd if=/dev/zero of=ubuntu.img bs=1m count=1024
   $ ls -lsh
   total 2097152
   2097152 -rw-r--r--  1 sarim  staff   1.0G Dec 18 02:42 ubuntu.img
   

3. Bullshit container creation done, now register this bullshit as disk in the system.

   $ open -a Disk\ Utility ubuntu.img
   

4. In Disk Utility, right click on the ubuntu.img in the left side pane. Select Open Disk Image from popup menu. It'll show a error msg.

5. Now check the disk listing, you'll see a new disk added at the end. It is /dev/disk6 for me.

   $ diskutil list
   
   /dev/disk6
      #:                       TYPE NAME                    SIZE       IDENTIFIER
      0:                                                   *1.1 GB     disk6
   

   Yay ! our bullshit disk is registered in the system

6. Now lets partition the disk. We are going to create a fat32 partition named UBUNTULIVE.

   $ diskutil partitionDisk /dev/disk6 1 MBRFormat fat32 UBUNTULIVE 100%
   Started partitioning on disk6
   Unmounting disk
   Creating the partition map
   Waiting for the disks to reappear
   Formatting disk6s1 as MS-DOS (FAT32) with name UBUNTULIVE
   512 bytes per physical sector
   /dev/rdisk6s1: 2093024 sectors in 261628 FAT32 clusters (4096 bytes/cluster)
   bps=512 spc=8 res=32 nft=2 mid=0xf8 spt=32 hds=128 hid=2 drv=0x80 bsec=2097150 bspf=2044 rdcl=2 infs=1 bkbs=6
   Mounting disk
   Finished partitioning on disk6
   /dev/disk6
      #:                       TYPE NAME                    SIZE       IDENTIFIER
      0:     FDisk_partition_scheme                        *1.1 GB     disk6
      1:                 DOS_FAT_32 UBUNTULIVE              1.1 GB     disk6s1
   

7. Now the UBUNTULIVE drive will be mounted in finder. Open Unetbootin. Select the iso, enter some how much space you want for persistance. Select /dev/disk6s1 in Drive. Click OK and Let it finish making the live disk. It happens in a snap in my ssd powered system, your experience may vary.

   

8. After unetbootin is finished, Go to UBUNTULIVE drive. Inside the drive, open syslinux.cfg in a text editor. (I used Textmate). Add the following lines at the end.

   label ubnentry6
   menu label ^Try Ubuntu without installing in Gittu way
   kernel /casper/vmlinuz
   append initrd=/casper/initrd.lz live-media=/dev/sda1 live-media-path=/casper/ file=/cdrom/preseed/ubuntu.seed ignore_uuid boot=casper quiet splash -- persistent
   

9. Save the file and unmount/eject the UBUNTULIVE drive.

10. GUI time is over, back to terminal. Now our image is ready. Convert it for virtualbox.

    $ VBoxManage convertfromraw -format VDI ubuntu.img ubuntu_vbox.vdi
    Converting from raw image file="ubuntu.img" to file="ubuntu_vbox.vdi"...
    Creating dynamic image with size 1073741824 bytes (1024MB)...
    

11. Phew! Done Now open virtualbox. Create a new vm/Edit Existing, in storage section, select Choose Existing Disk and select this ubuntu_vbox.vdi there. Boot the vm, in unetbootin menu, select the last option and press enter to boot.

    

Notes

• For linux, step 3 to 6 can be done using gparted. $ gparted ./ubuntu.img will do.
• This guide is based on ubuntu 13.10. A new boot flag live-media is needed for 13.10. That was taken from schmidi2.wordpress.com. If you are using another version, you may ommit the flag in step 8.
• Ubuntu ISO and 100MB persistent space fits in 1GB (1024MB) image, but if you want to increase persistent space, you need to increase image size (the count param) in step 2 too.

Now, this thing still wasted 2gigs of disk space, didn't it ? So whats the point ? There is none :v you may take it as bullshitting, or a scienctific experiment for educational purposes, your wish. Good luck and Happy linuxing (y)