rsync error between two TurnkeyFileservers, both on Proxmox

[holotone]

When trying to rsync between two different instances of TurnkeyFileserver both running on Proxmox, I keep getting this error on the same file:

rsync: [receiver] write error: Broken pipe (32)
rsync error: error in socket IO (code 10) at io.c(823) [receiver=3.2.3]
rsync: connection unexpectedly closed (7732 bytes received so far) [sender]
rsync error: unexplained error (code 255) at io.c(228) [sender=3.2.3]

Both TurnkeyFileserver instances are running version 3.2.3 protocol version 31 so it's not a version mis-match problem. One thing I am noticing is that when I'm trying to copy the destination TurnkeyFileserver CPU usage is 97.51% and Memory usage is 99.24% while on the source TurnkeyFileserver CPU usage is 0% and Memory usage is 75.89%.

Any ideas? Thanks!