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Important notice before downloading software

  • By downloading the software you agree with the license-conditions of the GPL (an open source license). You are strongly advised to read these conditions before you download the software.
  • The license states that the software is offered to you "as is", which means that guarantee and liability is limited.
  • If you want to use this software, please verify whether the software meets your requirements a.o. by reading the product-description on this web-site and the manual-pages delivered with the software-package.
  • To ensure that you have downloaded the authentic version of the cowloop-software, an MD5 checksum is delivered for every package. You can determine the MD5 checksum by running the command md5sum (or md5).
    Alternatively one can use the signature files (those ending in .sig) to verify the authenticity of the cowloop-software using pgp or gpg.
    Our public key,, has been uploaded to and can be found on many keyservers.
  • If you have any questions or remarks, please contact the maintainers of this software-package.


Download cowloop for Linux version 2.6.31

Version 3.2.0 and higher (Sep.2009) of cowloop: driver in mainline 2.6.32 kernel. Cowloop utils does not contain the kernel module anymore. This is a pre-release of the cowloop utilities for those wanting to experiment with the current development driver which is made ready for 2.6.32. See the "news" page to learn more.

Cowloop for Linux 2.6.31+
Package SHA-1 checksum / SHA-1
cowloop- 5f540648723484a9ab9f4ac315266d43f9428867 (sha1)
cowloop- Contains the SHA-1 hash for now



Download cowloop for Linux version 2.6

version 3.1 (Feb.2009) of cowloop: patches for Linux kernels up to 2.6.28.

Cowloop for Linux 2.6
Package MD5 checksum / Signature
cowloop-3.1.tar.gz f0a21029a46b085362e584cd591bd90d
cowloop-3.1.tar.gz.sig Please use "gpg --verify *.sig *.tar.gz"
Package MD5 checksum / Signature
cowloop-3.0.tar.gz da951eed8952bd05b8b372ed8a59b2e6
cowloop-3.0.tar.gz.sig Please use "gpg --verify *.sig *.tar.gz"
Package MD5 checksum / Signature
cowloop-2.15.tar.gz 70498b6c64df272b4e35d1af6b5e3659
cowloop-2.15.tar.gz.sig Please use "gpg --verify *.sig *.tar.gz"
Package MD5 checksum / Signature
cowloop-2.14.tar.gz 1b5e4c13d58c370e8b4d0baa73e00808
cowloop-2.14.tar.gz.sig Please use "gpg --verify *.sig *.tar.gz"
Package MD5 checksum / Signature
cowloop-2.11.tar.gz 1d5f25e2f57392620f68a4dfa5ede8ac
cowloop-2.11.tar.gz.sig Please use "gpg --verify *.sig *.tar.gz"

Download cowloop for Linux version 2.4

Version 1 of the cowloop driver can be used for Linux kernel version 2.4. Notice that this version of the cowloop driver is not actively maintained any more.
Its functionality deviates from the description on this web-site:

  • General
    The cowloop driver only supports one cowdevice (/dev/cowloop) that can only be activated by specifying the parameters rdofile= and cowfile= while entering the modprobe command.

    The size of the read-only file and cowfile is limited to 2 Gbytes.

    The cowloop driver modifies the bitlist more frequently to keep the cowfile in a consistent state (which means a performance-degradation compared to version 2).

  • Load & unload
    The optional parameter "option=" is not supported. There is no possibility to garantee the consistency of the cowfile.

  • Cowfiles
    A cowfile does not contain header-information. This implies that there is no possibility to verify whether an existing cowfile is related to the specified read-only file.

    The related commands to repair or query cowfiles are not delivered.

  • Status info
    The layout of the status-information retrieved by reading /proc/cowloop is different.
Cowloop for Linux 2.4
Package MD5 checksum / Signature
cowloop-1.4.tar.gz a80aafee62dca976dc0967ee474febbc
cowloop-1.4.tar.gz.sig Please use "gpg --verify *.sig *.tar.gz"




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