Error - Auto Archiving (no replies)

I'm having problems while attempting to auto archive. Here's the syntax:

su user -c "usr/bin/php /my/location/piwik/console core:archive --url=https://mywebsite.com/"

or

sudo su user -c "usr/bin/php /my/location/piwik/console core:archive --url=https://mywebsite.com/"

Results:

[InvalidArgumentException]                              
  There are no commands defined in the "core" namespace.

Any insight and assistance, is greatly appreciated!