I was a huge fan of Prescan back in the early betas of SharePoint 2007 (Prescan is your friend and Don’t be Afraid of Prescan) and would preach and preach people to run the tool (it’s all still true and much applies even more with PreUpgradeCheck).  Here’s 5 clear and solid reasons why you have to cozy up with PreUpgradeCheck.  The PreUpgradeCheck for preparing for SharePoint 2010 shipped with SP2, so if you have that or any of the cumulative updates you’ve got the goodness.  There is syntax and detail on the PreUpgradeCheck STSADM command on TechNet.

I’ve written about the PreUpgradeCheck in more detail in a previous post, as did our good buddies Bob Fox “PreUpgradeCheck in SP2” and Wictor Wilen in “Say Hello to STSADM preupgradecheck command.”

1. PreUpgradeCheck is has a better engine, it’s based on a best practices analyzer – Prescan had the job of making sure the database was consistent and wouldn’t fail when you upgraded.  It did a decent job of finding really bad things, but commonly would miss things that would matter.  Ask people why they hated in place upgrade in going from 2003 to 2007.  Why?  Cause it would fail for a ton of reasons that weren’t included in the prescan.  PreUpgradeCheck has an extensible rule base and can get better by simply adding rules.  The rules themselves are easily influenced.  You also have tons more detail and insight around your configuration and insight.  We also didn’t have workflows and content types and features to worry about in 2003 upgrade to 2007.

2. PreUpgradeCheck is read-only – For many this will be the number one reason they favor the likes of PreUpgradeCheck.  Prescan would “Prep” your database or even think about fixing things with your environment.  Really it simpy flipped a bit, but when the bit didn’t get flipped the upgrade would fail.  Now there’s no bit to flip.  BUT, if you forget to run the PreUpgradeCheck, you’ll find it’s not the end of the world.  Being read only most people will feel much more comfortable about running it in production.  YES!  Run it in production.  You need the data that it provides.  Sure you don’t have to start there, in fact I agree don’t start there, but get comfortable with the tool and run it not once but OFTEN!

3. PreUpgradeCheck Reporting Rocks!  Gives you not just a log and screen output, but an XML report and HTM report, and verbose log of all of the rules with a again verbose database and site collection detail that goes way beyond.  I love the idea of comparing the Local vs. Farm reports and comparing server to server reports.  I hope to hear how from small to large people are really leveraging this tool to keep things more synchronized than ever.  You’ll see there’s even more reason to leverage this reporting.  If you’re running PreUpgradeCheck once you’ve missed the point.  Even MS IT runs PreUpgradeCheck way before the upgrade, the hours or days before, and uses it as a cross check against any changes that may have happened.  Serious checks and balances.

4. PreUpgradeCheck tells you about the state of your farm – You did get some insight into your site collections in Prescan don’t get me wrong… from ghosting to site definitions, but you’ll see 10X the detail in PreUpgradeCheck.  I hope people realize the sweetness and insight.  It wouldn’t surprise me at all if people hit their last PreUpgradeCheck report after a disaster.  What else do you have that has all of your SharePoint webapps, your databases, your SSP config, and your AAMs, (seriously where do you have your AAMs written)  Why isn’t PreUpgradeCheck report part of your DR Plan???? IT SHOULD BE! 

5. PreUpgradeCheck is a native STSADM command and just as risky or unrisky as any other stsadm command - Presan was an insane install.  You had to download the bits and install them somewhere or find a 2007 install to grab the prescan executable.  It took about a year to even get it as a download center package.  Sad. What a mess!  Some customers were very scared of the tool.  Don’t let that fear from prescan carry over.  The mantra of the upgrade team… *DO NO HARM.*   With PreUpgradeCheck it’s on every farm that is running SP2 update or later.  Great stuff!  As a consultant you aren’t adding bits to run the check, it’s all native.  

As you can tell, there are a ton of reasons you should be running PreUpgradeCheck.  I don’t need to dis the PRESCAN to convince you, but those having any hesitation, this may help.