Dear Xianwen, > After searching on-line, it seemed that similar problems were reported > by other users of systemd. The fix is to set owner of / as root.root. > I tried the solution and it worked! I'm glad you fixed it. / not being root:root is strange. You may wish to sudo -i pacman -Qqkk to check for other odd permissions, etc., in case they too cause problems later. Note, it seems normal for some packages to cause grumbles from the above command. If a package is listed, I then do sudo -i pacman -Qkk atop to see more detail of the problem. Though unfortunately not enough detail, i.e. warning: atop: /var/log/atop/dummy_after (Permissions mismatch) doesn't tell me what they should be. One has to grovel around in the mtree file for that. $ zcat /var/lib/pacman/local/atop-*/mtree | > grep '^./var/log/atop/dummy_after ' | > fmt ./var/log/atop/dummy_after time=1549485614.0 size=0 md5digest=d41d8cd98f00b204e9800998ecf8427e sha256digest=e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 $ This entry doesn't have a ‘mode=...’ stating the desired permissions. mtree(5) doesn't say so, but I think it defaults to 0644 for files based on the other mode-less entries in that mtree file that don't cause pacman to complain. Not every error means the file on disk must be changed, perhaps it's a packaging problem, but it can be a useful aid. -- Cheers, Ralph.