What does the error “swap_pager: indefinite wait buffer:” mean?
This means that a process is trying to page memory to disk, and the page attempt has hung trying to access the disk for more than 20 seconds. It might be caused by bad blocks on the disk drive, disk wiring, cables, or any other disk I/O-related hardware. If the drive itself is actually bad, you will also see disk errors in /var/log/messages and in the output of dmesg. Otherwise, check your cables and connections.
