I am logged in as root and now cannot see a certain folder (u01/mnt/backup) via SSH putty or wincsp. Error message on putty when I type the command ls "cannot access backup: Permission denied". I have not seen this issue since I started managing this RedHat Linux server hosting our Oracle db 11g. The only change done was to revise the password of an ERP system account used to connect to this database and nothing else.