I am about to delete my website entirely from my server because I have 2 many bugs on my current websites and there are not fixable ( tried to do too many upgrade on on the top of each other and it is real mess )
I have duplicate content issues all over with multiple web address ( it is automatically created by my content management system and I no way to stop it )
My question is simple : If I load a brand new website on my current domain will all the bad url and duplicate content issue go away as soon as I load the clean website with the clean code or should I block the duplicate pages that " I know about that google currently has in its index with a robots.txt ?
Does the penalty that I currently have still applied with the new website or no ?
How long will it take for google to reindex my new website, drop the "bad" pages from the old website from its index and re-rank me.
the duplicate content problem goes away with a 404 response. (a 410 Gone might work faster) you replace that problem with the loss of link equity to those URLs. your links to the homepage will remain - good or bad. i wouldn't block anything that's a 404 unless crawl behavior gets unreasonable.