Getting rid of /dev/zram0
When you install the Raspberry Pi OS that is based on Debian GNU/Linux 13 (codenamed “trixie”), it uses a device /dev/zram0 for swapping to memory. That eats up valuable resources there (but is very fast). When your system has an SSD installed, you should consider to used a SWAP partition instead. How to setup this is explained quite well at various locations in the web.
What’s missing is how to to get rid of the /dev/zram0. There are a lot of different descriptions, especially when you ask your favourite AI, but none worked for me (at 2026-01-13). But finally I found the solution: remove the package rpi-swap (and, when you are at this point, also zram-tools), and the device is gone!
sudo apt purge rpi-swap zram-tools
sudo apt autoremove