We're about to have a major site infrastructure migration (new OS, upgraded PHP, etc).
We currently have a live test mirror of the new environment running, using the production file system.
We're expecting there to be some issues due to both the version change in PHP (let's just say PHP was very out of date on the old server and leave it at that) and changes in environment variables. Are there any good automated tools to quickly spider both sites so we can pinpoint issues faster than manually checking each page? I've already found a few manually, but anything which can double check in an automated fashion--especially across the entire site--would be lovely. I've searched around a bit but haven't found anything that seems to fit what we need. Maybe I'm just running the wrong keywords.
Multi step processes would be fine too, like spidering the site with a batch script/mass downloader and then running a folder diff. I'm coding from a windows environment but 'nix tools are fine too.