Scp-v viewing the specific process

A few days ago with colleagues discussed SCP multiple files and SCP multiple folders of the compressed package that fast.
The boss said, the compression package is fast, the compression packet transmission can avoid each file reconstruction connection, but the file system traversal, the directory creation, the inspection will have some overhead.
He suggested that I scp-v look at the specific transmission process.

The first time I heard that there is a-v this parameter, the test is as follows:

?  cbcq git:(master) ? scp -v Test.py local_server:/data/Executing: program /usr/bin/ssh host local_server, user (unspecified), command scp -v -t /data/OpenSSH_7.5p1 Ubuntu-10ubuntu0.1, OpenSSL 1.0.2g  1 Mar 2016debug1: Reading configuration data /home/cbb/.ssh/configdebug1: /home/cbb/.ssh/config line 2: Applying options for *debug1: /home/cbb/.ssh/config line 110: Applying options for local_serverdebug1: Reading configuration data /etc/ssh/ssh_configdebug1: /etc/ssh/ssh_config line 19: Applying options for *debug1: auto-mux: Trying existing masterdebug1: mux_client_request_session: master session id: 2Sending file modes: C0644 1101 Test.pySink: C0644 1101 Test.pyscp: /data//Test.py: Permission denied

This clearly shows the process of SCP transmission, reads local alias configuration, attempts to connect, insufficient connection permissions, and is denied.

Scp-v viewing the specific process