The final builds of CrunchBang Linux 8.10.02 are now available. This is the second revision of the third release of the distribution. As the version number suggests, it is based on Ubuntu Intrepid Ibex. As with previous releases, 8.10.02 has been built from scratch using the Ubuntu MinimalCD. The builds were completed on the 16th January 2009 and contain all security and packages updates available at the time from the Ubuntu repositories.

Method to download using zsync

As I have already downloaded ArtistX 0.6 which is also based on Ubuntu Intrepid Ibex and a friend has kindly emailed me the zsync file for CrunchBang, I will use the existing ISO and the zsync file to download the new ISO. This will both save bandwidth and guarantee a valid download of the file.

Constructing the code for the command line

Resources to use

Downloading CrunchBang Linux with zsync and ArtistX 0.6 as input.

Monday, 16th March 2009

Source file = E:\Linux-ISO-files\ArtistX\artistx_0.6_live_dvd_iso_02_14_2009.iso

.zsync file = crunchbang-8.10.02.i386.iso.zsync , which I have already on my hard drive after being sent it as an attachment to an email. [Size =

Command Line : --

in the E:\Linux-ISO-files\Crunchbang Linux directory

zsync crunchbang-8.10.02.i386.iso.zsync -i  E:\Linux-ISO-files\ArtistX\artistx_0.6_live_dvd_iso_02_14_2009.iso

only in need to switch over to a live session in Linux to do this, and that will change the path in the above line.

Recording the actual download

Further Experiment 

As a further experiment in distributing .zsync files, I have another, much smaller file, which should update the above .zsync file from an 'earlier' version. [In this case it will be the same, but just testing for now ...]

zsync crunchbang-8.10.02.i386.iso.zsync.zsync [This is only 5 KB in size compared with 1,378 KB for the main .zsync file]

Well this part of the experiment seems to have succeeded admirably.

Setting up the process.

I created a sub-directory and moved the small updating file into that so that I could re-create the target file to update the ISO itself without interfering with the already existing copy.

I then constructed the normal zsync command, like this : --

     crunchbang-8.10.02.i386.iso.zsync                    - updating to this file, the target.

     with

     zsync and crunchbang-8.10.02.i386.iso.zsync.zsync    - a very small 'recipe' for the above.

     from

     http://pgtips91.pbwiki.com/f/crunchbang-8.10.02.i386.iso.zsync   - indicated with the -u switch

     using, as an input an 'earlier' version of the target file, in this case an identical copy

     ../crunchbang-8.10.02.i386.iso.zsync  - indicated with the -i switch [../ means in the parent directory]

So this is how it looks, in one continuous line : --

zsync crunchbang-8.10.02.i386.iso.zsync.zsync -i ../crunchbang-8.10.02.i386.iso.zsync -u http://pgtips91.pbwiki.com/f/crunchbang-8.10.02.i386.iso.zsync

The Results.

This ran in a split second [0.060 sec real], produced the 'new' crunchbang-8.10.02.i386.iso.zsync file, verified the result and exited.

The usefulness of this information.

Using this technique it would be possible to distribute the.zsync file to someone who already had a previous version just by emailing them a very small attachment [5 Kb in this case] with which they could download the new .zsync file, verify its md5sum, at very little cost of time or bandwidth.

Since the use of zsync to update the ISO itself can have huge savings, where there is a series of ISOs being released in succession, for testing, etc, this could speed the whole process as well as keeping bandwidth down to a minimum.

Now all that is needed is to write a simple script that can do everything just by being invoked in a Konsole window.

Paul

Monday 16th March, 2009