system:

kernel: [27239.988446] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro
..

auth.log
: TTY=pts/8 ; PWD=/home/{removed} ; USER=root ; COMMAND=/bin/mount -n -o remount,rw /
{removed} sudo: pam_unix(sudo:session): session opened for user root by {removed}(uid=0)
{removed} sudo: pam_unix(sudo:session): session closed for user root