Release notes

These release notes describe system requirements, installation instructions, and known issues for zsplit/unzsplit tools. These notes will be updated as we receive feedback, so please check back for new information. Click here to provide feedback on zsplit/unzsplit. These release notes were last updated 5 June, 2005.


What is new in zsplit/unzsplit

version 1.2.0

A lot of work has been done in order to optimize the read/write speed and compression rate. The read/write speed has been improved for zsplit up to 7-10%, for unzsplit up to 50% (nearly two times faster). Compression rate has been improved up to 2-5%; in some cases the compression rate was 1-2% better then the compression rate of the same level for gzip.

Obviously, the read/write speed depends not only on the size of buffer cache of the hard drive but also on the size of read/write buffer of zsplit/unzsplit.The new option (-b, --buffer) enables the adjustment of the read/write buffer size to tune both tools in order to farther improve the read/write speed for particular combination of hard drives.

For people who saves split images on several CD's or DVD's the new option in unzsplit (-m, --multivol) allows a paused restore operation. With this option you can change volume containing split chunks during the restore operation and, after that, continue the restoring.

The noerror option (-r, --noerror) has been optimized in order to minimize the amount of skipped/replaced bad sectors.

version 1.0.1

Improved logging information: elapsed time and average speed of imaging, man pages for zsplit and unzsplit are now accessible.


Installation Notes

To compile and install the sources archive please do the following:

  1. unpack the tar archive (example: tar -xvzf zsplit_src-1.0.1.tar.gz)
  2. cd into the new directory (example: cd zsplit-1.0.1)
  3. run ./configure
  4. run make
  5. run make install (please notice, you should have root rights to do this step). After installation you can access man pages: man zsplit or man unzsplit. For details of installation, please see INSTALL notes included in the distribution archive.

To install packages please do the following:


dpkg -i package_name.deb (please replace package_name.deb through zsplit_1.2.0-1_i386.deb or unzsplit_1.2.0-1_i386.deb)


rpm -i package_name.rpm (please replace package_name.rpm through zsplit-1.0.1-1.i386.rpm or unzsplit-1.0.1-1.i386.rpm)

Known Problems
Program version Short description status fixed in
zsplit/unzsplit 1.0.1 Bug in calculation of average speed of imaging fixed v. 1.2.0
zsplit 1.0.1 "Success!..." message after abort of operation in case of I/O error fixed v. 1.2.0
zsplit 1.0.0 zsplit: file name does not exist: /dev/xxx, in: treat_file() fixed v. 1.0.1


Detailed description and workarounds:

Bug in calculation of average speed of imaging

Sometimes after image- or restore operation you can see weird values for "average speed of imaging" something like -2147483648MiB/min. This bug is fixed now.

"Success!..." message after abort of operation in case of I/O error

If you start zsplit without "-r" option to make an image of device/partition which containes bad sectors you may see the "Success..." message at the end of operation. The amount of read bytes does not correspond to the size of this device/partition. This bug has been fixed. If I/O error ocured and "-r" option was not used the error message and "not succeeded..." info properly indicate the situation.

zsplit: file name does not exist: /dev/xxx, in: treat_file()

If you start zsplit in order to make an image into the current directory like: zsplit -s 780M -N some_name -d /dev/hda, you get an error message "zsplit: file name does not exist: /dev/xxx, in: treat_file() zsplit: not succeeded..., error in operation!"


  1. Please start zsplit in the /dev directory with explicit option "output directory";
  2. example: cd /dev then zsplit -s 780M -N some_name -o /out/dir -d /dev/hda
  3. The image from /dev/hda will be written into the directory /out/dir

Acknowledgement: Michael Thonke and Michael Giel de Rooij for reporting this bug.


Copyright(C) 2005 - 2007 DeviceImage-Project

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07.07.2007: DeviceImage software goes commercial. Please see here for details.

28.11.2006: Broadening multilanguage option of the homepage. Italian translation has been added. Thank you very much Gianfranco!

14.03.2006: Added mini-HowTo your feedback is very appreciated

27.09.2005: Broadening a multilanguage homepage, Spanish translation has been added, thank you very much Jose!

05.06.2005: zspli/unzsplit version 1.2.0 has been released, please see release notes. Also DeviceImage-LiveCD is now available.

08.04.2005: started multilanguage version of DeviceImage homepage + Forum.

06.03.2005: zsplit/unzsplit version 1.0.1 has been released, please see release notes.