provides utilities to back up and restore used-blocks of a partition [...]

My environment is a VMware virtual machine bootstrapped with the Arch Linux ISO and with the following mounted storage:

  • sda, which is a physical USB flash disk,
  • sdb, which is a virtual disk (VMDK).

Details follows in the figure:

Disk list

df command output shows that only 527 MB are used on /dev/sdb1. I assume the actual used blocks can be copied onto /dev/sda1, whose size is 858 MB.

The related Partclone command and output follows:


Can you give some hints on the error shown in the figure above?
Can Partclone actually perform a copy only of filesystem used blocks, therefore saving space?
Or is this feature intended only to make Partclone faster and not to save space?
If the approach suggested here is mistaken, can you suggest the proper way to copy a filesystem used blocks?

Update. A typo has been fixed where /dev/sda1 was misspelled as /dev/sdba1

2 Answers 2


/dev/sdba1? That looks like a typo to me. Is it possible that this partclone.fat32 tool has now created a file (not a device) /dev/sdba1 that filled up the root filesystem of your VM? Post the output of

ls -l /dev/sdba1

then we can tell you for sure.

EDIT: you are trying to clone from a 4 GB block device to a 850 MB block device. Are you sure that partclone.fat32 is able to reduce the filesystem size automatically? Maybe this is your main issue. Try to add another virtual disk, once with the same size as /dev/sda and once with the same size as /dev/sdb and try to clone on them both. If the first doesn't work, but the second does, then the target device size is too small.

  • Right you are, but restarting the machine from the Arch ISO deletes /dev/sdba1. Anyway typo was corrected, but problem remains, see new pics.
    – antonio
    Sep 26, 2013 at 11:21
  • What I am testing here is the actual capability of partclone to understand filesystems and copy/clone only used blocks, since I am dissatisfied with tools requiring same size devices. In the first screenshot you can see that I mounted sdb1 and run df -h /dev/sdb1 exactly to show that the its size is 527M, so it can fit sda, which is 858M.
    – antonio
    Sep 26, 2013 at 13:35
  • @antonio But are you certain that it is actually able to reduce the filesystem size? "Clone only used sectors" could very well mean that fewer bytes are transferred (by only transferring used sectors), but that the filesystem structure and therefore its size remain unchanged. Sep 26, 2013 at 13:48
  • @antonio well, it seems like you've found another tool that requires the same device size. I may be wrong because I've never used partclone, but it sure looks to me as if it doesn't support resizing. Sep 26, 2013 at 14:09

Command is correct except the typo /dev/sdba1

Revise the command and you will get the desired result

  • Typo corrected, but problem remains, see new pics.
    – antonio
    Sep 26, 2013 at 11:22
  • Look like, /dev/sdb1 is out of memory. Try by freeing up /dev/sdb1/ or increasing it's size
    – SHW
    Sep 26, 2013 at 11:37
  • sorry, don't get it. /dev/sdb1 is a physical flash pen, created with YUMI. How do I increase its size ?
    – antonio
    Sep 26, 2013 at 12:39

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