I often copy many files between 2 servers connected via 1GBit ethernet while I am connected via VPN and SSH over DSL. The problem is, that the verbose output (1 line per copied file) which needs to be sent over the slow connection to my ssh client and slows down the copy operation (it feels for me this way)
I tested this with a testfile created via
dd if=/dev/urandom | base64 | dd of=testfile count=10M bs=1
Testing run A (no output)
# time sh -c 'cat testfile > /dev/null' sh -c 'cat testfile > /dev/null' 0.00s user 0.02s system 97% cpu 0.025 total
Testing run B (all output via ssh/vpn)
# time sh -c 'cat testfile' sh -c 'cat testfile' 0.00s user 0.45s system 0% cpu 4:31.10 total
(I know, its not a good test, but it demonstrates the problem)
Is there a way not to slow down the operation and get the output asyncronously. I imagined something like dropping all lines except a specified count per second or something like this.
At the moment I start screen and detach while the operation is running.
I am using putty for windows and the openssh-client for linux access