This is useful if you want to keep track of how Rebuild is progressing. We recommend that you don't use the -v option if you are redirecting the output to a file.
Parameters
n If you specify the /f option, Rebuild displays a '"." character every n records. If you do not specify the /f option, Rebuild displays a a record count every n records. If you do not specify the n parameter, Rebuild displays information about its processing phases.