PiMix is a remixed version of Ubuntu for the Raspberry Pi 4 that is optimized for desktop use.
Ubuntu 21.04 was released in April. This version is being released in September since I wanted to switch over to BTRFS for the root file system. BTRFS enables the creation of filesystem snapshots which can be used to restore the system to an earlier state. This is useful for recovering from bad system upgrades and software issues. BTRFS also supports transparent compression at the filesystem level. This saves disk space, boosts storage performance, and makes the desktop more responsive when installed on an SD card.
PiMix Config tool can now save and restore layouts for the XFCE desktop. A few simple layouts are included. You can create your own layouts by customizing the desktop and saving the changes.
What’s New
BTRFS with ZStd Compression
The root filesystem uses BTRFS with zstd compression. BTRFS enables the creation of filesystem snapshots which can be used to restore the system to an earlier state. This is useful for recovering from bad system upgrades and software issues. BTRFS also supports transparent compression at the filesystem level. This saves disk space, boosts storage performance, and makes the desktop more responsive when installed on an SD card.
Due to compression, less data needs to be read and written to disk. This gives a boost to read/write performance and extends the lifespan of flash-based media (SD cards and SSDs). The compressed filesystem takes around 60% less space compared to the uncompressed filesystem. PiMix can be installed on an 8 GB SD card with 4 GB of room to spare.
System Snapshots
Snapshots can be created and restored using the PiMix Config tool.
Snapshots are useful for recovering from bad system upgrades and software issues. Create a snapshot before doing system upgrades and restore the snapshot in case of any problems. The system can be restored to a good state using snapshots even if it no longer boots. Boot from another PiMix SD card and restore a previous snapshot on the non-bootable SD card.
This is also useful for experimenting with software. You can experiment with installing new desktops, kernels, drivers, and other software. Reset the system after you finish experimenting, or keep it as a snapshot in case you wish to continue experimenting in the future.
Here’s a screenshot of some snapshots on my system. Each of these snapshots is a different experiment that I was doing. I can restore any of these snapshots, reboot, and continue from where I left off.
Restoring snapshots is a non-destructive operation. Your current system state (prior to restoring the snapshot) will be preserved as a new snapshot. You can restore this new snapshot later to “undo” the restore.
The snapshot functionality provided by PiMix is meant to be simple to use and requires zero configuration. Since the Raspberry Pi 4 lacks a real-time clock, the system time is not reliable. There are no scheduled snapshots. Snapshots must be created and deleted manually when required.
Xfce Desktop
Various optimizations have been done to the desktop configuration to improve responsiveness. The Xfce desktop uses a bottom panel layout with modern themes and icons. You can create or change layouts using the PiMix Config tool.
Software
The DEB version of Chromium from Debian’s Buster repository is included, instead of the Snap version from Ubuntu repositories. Firefox is also included as an alternative.
UBlock Origin is pre-installed for blocking Ads. This enables web pages to load faster since less content needs to be downloaded and displayed.
PiMix Config tool now has a section for removing pre-installed software. The “Slim Desktop” option will remove most pre-installed applications except Chromium, accessories, and system tools. The “Barebones Desktop” option will remove everything and keep only the minimum packages required for a working desktop.
A snapshot is created before packages are removed. You can restore the snapshot and reboot to the previous state if needed.
An option was added to change the CPU governor.
Calamares Installer
The first-boot setup is now done with Calamares. It will create a primary user, and configure the timezone, keyboard, and locale.
The setup done by Calamares is super-fast and completes in 3 minutes. A system snapshot is created after the setup is complete. This snapshot can be restored later to reset the system to factory settings.
Download
This release of PiMix is available for download for $6. This fee pays for the servers where downloads are hosted. Downloads are hosted on fast servers with direct download links and no Ads. This fee does not include support. Since this distribution is based on Ubuntu, you can find solutions to issues online by doing a quick search on Google.
The lifetime subscription option is no longer available. If you previously purchased a subscription then you will continue to receive all future versions. Please check your email for the download links.
You can upgrade to Ubuntu 21.10 when it is released using the normal upgrade process for Ubuntu. Create a system snapshot before upgrading so that you can restore the system in case of issues.
PiMix 21.10 images will be available in November.