TempFS and SystemD questions - During and after installation

So,
I’ve completed first step re-building my system and getting a close look at the Installer and decisions which can be made, particularly during the Partitioning steps.

According to the 12.2 Release Notes, systemd is supposed to automatically and by default create tempfs mount points for /run, /var/run, /var/lock and /media. I noticed during Install that tempfs mount points can be explicitly configured for the first few listed and /tmp

  1. Assuming running systemd, am i to assume then that there is no need to create tempfs mount points for any of the possible choices except for /tmp (which seems to be one of the folders not configured for tempfs automatically by systemd)?

  2. Is there a particular CLI that can verify that systemd did indeed mount those folders in tmpfs? I’m used to running fstab to report this information, but of course that won’t work for tmpfs.

  3. I arbitrarily decided to go ahead and create a tmpfs mountpoint for /tmp, but I’m curious about its effect on a number of files I’ve observed cannot and should not be removed while a system is running, for example KDE related files. I assume that these files will simply be re-created with next User Login without much of an issue or could this theoretically be a <negative> bootup/login performance issue?

  4. Whatever decision is made about tmpfs mountpoints during install, would changing later after installation be much of a problem?

TIA,
TSU

  1. Is there a particular CLI that can verify that systemd did indeed mount those folders in tmpfs? I’m used to running fstab to report this information, but of course that won’t work for tmpfs.
systemctl status *.mount
grep -i tmpfs /proc/mounts

When I create a tmpfs file system for “/tmp”, I simply edit the entry into “/etc/fstab”. The tmpfs file system won’t exist until the next boot.

That way, I don’t have to worry about messing with what is already running.

I think it’s not just a KDE or other desktop login. The Xorg server also puts stuff in “/tmp”.

After the reboot, when I have checked that the tmpfs mount is there for “/tmp”, I do:


# mount --bind / /mnt

and then the old “/tmp” is visible as “/mnt/tmp” where I can clean out everything left behind from the prior boot, then unmount “/mnt”.