On Sat, Mar 20, 2021 at 11:37 AM Andreas K. Huettel <dilfri...@gentoo.org> wrote: > > Hi all, > > why do we *copy* the timezone file to /etc/localtime, instead of symlinking > it like everyone else? > > 1) Our handbook recommends: > > echo "Europe/Brussels" > /etc/timezone > emerge --config sys-libs/timezone-data > > which is effectively doing > > echo "Europe/Brussels" > /etc/timezone > cp -f /usr/share/zoneinfo/Europe/Brussels /etc/localtime > > 2) Most other distros seem to just do > > ln -sf /usr/share/zoneinfo/Europe/Brussels /etc/localtime > > and use the link content as timezone name (this is also what is required by > systemd). > > Does anyone remember the reason for 1) ? Or is that lost in history?
I think the most obvious reason would be to support late-mounting of /usr, after the system clock has been reset with a UTC offset on boot. To make this work, the /etc/localtime file would need to be available when the hwclock init script runs. These days, I suspect there are not many users running systems with a hardware clock in local time, and a separate /usr filesystem, and no initramfs to mount /usr early. I created a PR to adjust the logic in timezone-data to promote symlinks for new installs, while keeping regular files in place for existing users. https://github.com/gentoo/gentoo/pull/20050 If we added some logic to detect if /usr is a separate filesystem, we could possibly be even more aggressive about this. But I'm not sure I want to rock the boat that much in one commit.
