swap_pager indefinite wait buffer - question

[PeerCorps Trust Fund]

I am not sure if this should be classified as a bug, but I've been testing a basic DragonflyBSD install in order to how well an idea to use external USB disks could work.

What I seem to get repeatedly is a complete stopping of copy to disk operation and the following list of scrolling text:

swap_pager: indefinite wait buffer: offset 1783230464, size: 4096
swap_pager: indefinite wait buffer: offset 125403136, size: 4096
swap_pager: indefinite wait buffer: offset 864153600, size: 4096
swap_pager: indefinite wait buffer: offset 1893855232, size: 4096
...
...

This is reproducible each time any time I try to copy over large folders. Each folder is around 100 gigabytes with random content.

The DragonflyBSD install itself is a base installation only. The initial install was made on a Thinkpad X200 with a Sandisk 128 gigabyte SSD. The only parameter changed was selecting a larger space for swap (around 40 gigabytes) and enabling the following in /etc/sysctl.conf

vm.swapcache.read_enable=1
vm.swapcache.meta_enable=1

After a series of NFS exports are made, and the HAMMER formatted external Western Digital Passport disk is plugged in to the USB port I've copied items via the terminal from a second machine on the network to the disk. After about 15 minutes or so of copying the above happens.

Is there anyway to stop this from happening?

I've noticed that after a while the external disk does go into standby mode, but the server must be cold restarted (it becomes unresponsive) and the system on which the copying is done also needs a restart as the GUI hangs. But my only concern at this point is the DragonflyBSD machine and how to stop the above messaging and stalling of copy operations.

Any information would be extremely appreciated!