atconsultancy logo
cowloop logo
atcomputing logo

small @ logoHome



spacerFAQ Logo


Welcome to the COWLOOP home page

The cowloop driver is a copy-on-write loop driver (block device) to be used on top of any other block driver. The cowloop driver shields the lower driver from any write accesses. Instead, it diverts all write-accesses to an arbitrary regular file.

The cowloop driver has been developed for ATmission, the Linux Live-CD of AT Consultancy.


The authors deny any warranty for any data loss and damage whatsoever that may be caused directly or indirectly by using this software. This is experimental software. Use at your own risk.

This software is licensed under the GNU GENERAL PUBLIC LICENSE version 2, as stated in the source code.


The authors intend to support the cowloop software in the future. You will see new versions and more capabilities.

We will consider to integrate any modification to the cowloop driver that will be sent to us. If we decide not to incorporate a modification, we will place it as a patch or patch-set together with similar contributions. Obviously there will be a notice about the reason that a particular patch was kept separate.




spacerLoad & unload



spacerStatus info

spacerExample 1

spacerExample 2

spacerExample 3

spacerCowloop vs.
   device mapper

spacerView as single page

© AT Consultancy bv, Nijmegen, The Netherlands  -
© AT Computing bv, Nijmegen, The Netherlands  - -