I noticed that fstrim wasn't working on my new Ubuntu 24.04 desktop installation, failing with "fstrim: /: the discard operation is not supported". In that setup, Ubuntu is installed into an LUKS encrypted LVM volume, so the ext4 file system, LVM and LUKS need to play nicely together for flash discard to work. That's how … Continue reading Trim on LUKS encrypted LVM root volumes