I have a bootable 32 GB Ubuntu USB stick with persistent storage.

The 32 GB USB stick is getting full, so I want to clone it into a 64 GB USB stick and increase both the casper-rw and the usbdata partition.

How can I do it without losing any data?

Here is how I cloned the 32 GB USB stick into the 64 GB USB stick. First, I issued the following command:


and got this result: lsblk result on terminal

Second, I used the DD command:

sudo dd if=/dev/sdb of=/dev/sde status=progress

Third, I powered-off the computer, removed the 32 GB stick and powered on the computer. The system booted correctly from the new USB stick and it seems that all the files are there.

Forth, I loaded the GParted utility and here is the snapshot: GParted snapshot

Now back to my original question: How do I proceed in order to increase the casper-rw and usbdata partitions using the free/unallocated space without losing any data?

  • dd will clone smaller disk to larger, sudo dd if=/dev/sdx of=/dev/sdy where sdx is source and sdy is target. dd can be dangerous use with caution. – C.S.Cameron Oct 6 '19 at 4:27
  • The process is a bit involved if you do it manually. Literally, you can recreate all the partitions manually and then rsync -avp all the files but it will require editing grub.cfg and /etc/fstab by replacing the specified UUIDs. Is the UFD MBR or GPT? You will need to have GRUB installed on the MBR or have an EFI sys partition and bootx64.efi. – marko Oct 6 '19 at 5:26
  • Please do not post screenshots of the terminal. Paste the text directly to your question and apply code formatting. – Melebius Oct 9 '19 at 13:13
  • 1
    Possible duplicate of How to resize partitions? – Melebius Oct 9 '19 at 13:13

Clone with mkusb

You can clone from a drive to another drive with mkusb. Start via the graphical interface or with

dus /dev/sdx

where x is the device letter or the source in the cloning operation. The target will be selected in a safe way via menus.

  • mkusb wraps a safety belt around dd
  • if there is a GUID partition table, GPT, mkusb fixes the backup partition table at the tail end of the drive. (Otherwise you must do that manually for example with gdisk.)

After the cloning you can edit the partitions with gparted. If you touch only the casper-rw partition and the usbdata partition (amd if an MSDOS partition table the extended partition), booting will not be affected.

Edit: How to edit the partitions to fill the drive.

  • Be sure you have a backup (for example the original drive).
  • Read how to use gparted.
  • Boot from another drive
  • Unmount all partitions on the target drive
  • Start gparted and check that there are no lock symbols on /dev/sdb1 and /dev/sdb5.
  • Move /dev/sdb1 to the tail end (to the right)
  • Drag its left border of /dev/sdb1 to the left until the size is what you want
  • Drag the right border of /dev/sdb5` to the right to use all remaining unallocated drive space. The two partitions should 'touch each other'.
  • Check that things are as you want them.
  • Click on the tick icon to start the actions.
  • Please wait ... it will take a long time. Be sure there is enough power (do not run on battery).

If you cloned with dd you need to repair the backup partition table at the tail end of the drive with gdisk or maybe use gpt-fix.

Edit: gdisk command options cut from gpt-fix

echo \
y" \
| gdisk "$1"

where "$1" should be replaced by the target device /dev/sdx, if run directly (not within the shellscript).

These command letters are explained in

man gdisk

The crucial commands are

in the expert's menu

   e      Move backup GPT data structures to the end of the disk. Use this
          command if you've added disks to a RAID array, thus  creating  a
          virtual  disk with space that follows the backup GPT data struc‐
          tures. This command moves the backup GPT data structures to  the
          end of the disk, where they belong.

and in the the recovery & transformation menu

   d      Use  main  GPT  header  and  rebuild  the backup. This option is
          likely to be useful if the backup GPT header has been damaged or

The other commands are verifying, moving between menus and writing.

Links added by the OP, @BlueSkies:

Unable to unmount a partition with GParted - is this a problem?

GParted cannot finish step 1

GParted showing now

After cloning with mkusb, copying partitions from the original USB stick and booting from the new-larger stick, I'm unable to access the usbdata.

Access to usbdata partition blocked

Please advice. Thanks!

Advice: Please post the output of the following command lines (when booted from the new-larger stick),

sudo lsblk -f
sudo lsblk -m
sudo ls -l /mountpoint-to-usbdata
sudo ls -l /mountpoint-to-casper-rw

where you enter the actual mountpoints to see usbdata and casper-rw.

This will help me understand what is the problem, so that I can suggest what to do next.

Please edit your original question to enter these output texts instead of here in my answer. Indent each line 4 characters in order to render the output as code. You can mark (high-light) the text and click on the {} icon at the head of the editing window to make those indentations quickly.

Outputs of the four above-mentioned commands:

The command sudo lsblk -f gives the following results

enter image description here

The other one (sudo lsblk -m) outputs the following info:

sudo lsblk -m results

The last two commands and results:


enter image description here

| improve this answer | |
  • 1
    It is enough to unmount the partitions that are involved in the editing (and you will not touch the sde4 partition with iso9660). – sudodus Oct 11 '19 at 16:32
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    You had bad luck :-( This is what happens sometimes. Editing partitions is risky. But I think you have still got the original 32 GB USB stick with the correct data. Now I suggest that you use mkusb and create a fresh persistent live system (with exactly the same system (from the same iso file) in the new 64 GB USB stick. Then you can use sudo rsync to copy the directory trees in the original casper-rw and usbdata partitions to the corresponding partitions in the new drive. – sudodus Oct 11 '19 at 21:52
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    sudo rsync -Havn /mountpoint-of-original-usbdata/ /mountpoint-of-new-usbdata/; (one line); Check that the output looks good, and then remove the option n and do the real thing. – sudodus Oct 11 '19 at 21:55
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    sudo rsync -Havn /mountpoint-of-original-casper-rw/ /mountpoint-of-new-casper-rw/; (one line); Check that the output looks good, and then remove the option n and do the real thing. -- Read man rsync in order to understand the details, for example the trailing slash after the source: source/ – sudodus Oct 11 '19 at 21:56
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    It should be possible to read and write in /media/ubuntu/usbdata. You need elevated permisisons to read and write directly into '/media/ubuntu/casper-rw` because its first level of directories is owned by root.But it should be overlayed with the system partition /. and you should be able to read and write as usual into your home directory, which should be saved automatically in the casper-rw partition (at /media/ubuntu/casper-rw/upper/home/ubuntu – sudodus Oct 13 '19 at 13:34

You could try ddrescue or gddrescue.

sudo apt-get install gddrescue ddrescue
ddrescue /dev/sda /dev/sdb -v
| improve this answer | |

Just open ubuntu and install gparted, umount all partitions that you want to clone. Select partition from usb A in Gparted and copy >> paste to another usb B.enter image description here

| improve this answer | |

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