用 man scp 看的 -l 是限速配置
-l limit
Limits the used bandwidth, specified in Kbit/s
scp: illegal option -- h
usage: scp [-1246BCpqrv] [-c cipher] [-F ssh_config] [-i identity_file]
[-l limit] [-o ssh_option] [-P port] [-S program]
[[user@]host1:]file1 ... [[user@]host2:]file2