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Automated and efficient updating of EasyOS

July 29, 2020 — BarryK

This is very exciting. It has been on the to-do list since the early days of EasyOS.

Users will know that you can update EasyOS to a new version by downloading the latest 'easy-*.img.gz' file, clicking on it to uncompress (.img.gz to .img), then click again to open it up. Then the files 'vmlinuz', 'initrd' and 'easy.sfs' can be copied to the boot-partition of the current installation, then click on 'initrd' to "fix" the BOOT_SPECS file inside the initrd.

That is fairly straightforward, but having to "fix" the initrd is an awkward extra step, and sometimes people forget.

Also, the 'easy-*.img.gz' file is over 500MB, so it is a big download, especially if you are on a pay-as-you-go or limited data account. Also, downloading from can be slow. What we really want is to only download the "differences" between current 'easy-*.img.gz' and the latest 'easy-*.img.gz'...

Introducing EasyUpdate, that automates the update, so you don't have to do that "fix" step, and has the efficient "differences" download.

I have built Easy 2.3.5, and booting it, there is a new icon on the desktop, labelled "update":


Click on "update", and EasyUpdate starts, with an introductory message:


This first version is a CLI application. I will probably add a GUI down-the-track, but for now, CLI works fine.

After pressing the ENTER key:


Each operation spits out to the terminal, so you have something to watch while it is doing it's thing.

In this case, there is no later version than 2.3.5, so the script terminates. However, if a later version is online, then things get very interesting...

Let's say that there is 'easy-2.3.6-amd64.img.gz' online. Rsync will compare with a local 'easy-2.3.5-amd64.img.gz' and only download the differences.

However, and this is the really interesting bit, if you don't have 'easy-2.3.5-amd64.img.gz', which is probably the case when you are doing these "difference" downloads, no problem, the script will create 'easy-2.3.5-amd64.img.gz'.

What the script does, is rebuild 'easy-2.3.5-amd64.img.gz' using the current 'vmlinuz', 'initrd' and 'easy.sfs' files. Currently, it is leaving out refind and syslinux boot files, but that doesn't matter much -- will cause only slight differences in the file. This file is only temporary, just used by rsync.

There is a requirement when woofQ creates the 'easy-*.img.gz', it uses the 'gzip' utlity to compress the .img file to .img.gz. The change now is the "--rsyncable" option must be used, for example:

# gzip --rsyncable easy-2.3.5-amd64.img

That option makes it easier for rsync to discover common chunks within the two .img.gz files. However, it does make the .img.gz file a bit bigger. I found that 'easy-2.3.5-amd64.img.gz' compressed normally was 520MB, compressed with "--rsyncable" was 544MB.

However, and this is the important bit: I did a test upgrade from 2.3.4 to 2.3.5, the former was reconstructed by the script, I uploaded the latter, then ran rsync, and it only downloaded 45MB and created 'easy-2.3.5-amd64.img.gz'.

This is fantastic, 45MB, compared with a full download of 544MB!

That's enough for one post. There will probably be a tutorial written sometime.

Changing the subject, 2.3.5 has another new desktop UI feature, more options in the Shutdown menu:


These are all great new features! 

Tags: easy