About once an hour I get this e-mail

In my Cron Tab, this is the command it runs...

This is obviously one of the default Cron Jobs that is in Plesk. Will anyone be kind enough to fill me in on what this job is trying to do, and possibly why I'm getting this error message almost every hour. I'd like to fix it and make sure thats its running correctly. My gut tells me this is some kind of backup job ( not sure if its a backup of Plesk itself or not ) and if it is, I'm worried that I'm not getting backups that I should be.

I appreciate any help!