Copying large files get stuck (Debian)

[alechko]

Hey,
When trying to copy cloudserver image (~1GB) from mounted container, the copy gets stuck.
I'm using iftop to monitor network, and while the copy starts with reasonable transfer rate, it decreases with progress, and at some point it gets stuck.
When trying to kill cp / cloudfuse processes, the container hangs and ls -la gives:
d????????? 0 user user 4096 Sep 19 22:36 mountpoint