Thank you! You are right, what I did is based on that link: https://www.archlinux.org/news/binaries-move-to-usrbin-requiring-update-intervention/ Now, for my problem, is there any way to repair that? Or you think I should reinstall my arch linux system? Renzhi Cao Email : rcrg4@xxxxxxxxxxxxxxxxx ________________________________________ From: arch-general <arch-general-bounces@xxxxxxxxxxxxx> on behalf of Ralf Mardorf <ralf.mardorf@xxxxxxxxxxxxx> Sent: Friday, March 7, 2014 12:27 AM To: arch-general@xxxxxxxxxxxxx Subject: Re: Problems of using pacman and updating the filesystem PS: > https://wiki.archlinux.org/index.php/arch_filesystem_hierarchy It does link to https://www.archlinux.org/news/binaries-move-to-usrbin-requiring-update-intervention/ ;)