I've been using the same Archlinux install over the past 12 years or so. Initially installed in 2006 (version 0.7 or so), I only re-installed properly when I switched from 32-bit to 64-bit packages, and from ReiserFS to Ext4 in the same step. Since then I've been using the same install on my personal computer, and just rsync-ed the files between hdds, laptops, etc.
It's been pretty stable, had some hiccups a dodgy kernel once I think. Can't remember what it was specifically.
> zcat /var/log/pacman.log.1.gz-2018010214.backup | head -1
> [2009-02-23 18:14] installed filesystem (2009.01-1)