When trying to copy file using distcp on H23, if -m 0 is specified, distcp will just spawn 0 mapper tasks and the file will not be copied.
But this used to work before H23, even when -m 0 specified, distcp will always copy the files.
Checked the code of DistCp.java
Before the rewrite, it set the number maps at least to 1
But in the newest code, it just takes the input from user: