Install/Upgrade System

Directory not writable! /data/web/
Please correct by executing: chmod 777 or set writing permission for php process, exiting! ?

Warning: Unknown: write failed: No space left on device (28) in Unknown on line 0

Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/var/lib/php5/sessions) in Unknown on line 0