After updating it to SP2, what do I need to check to be sure everything still works fine? It could be nice to write a checklist.
This is very vast area, it's depend how you want test it. I can share you my experience which will give you idea.
1) make sure you farm properly upgraded to new build number
2) from CA, Upgrade and migration page> review database status....make sure all db upgraded and no action required.
3) from CA, manage server in farm...make sure all server status shows as no update required.
4)make sure time service & admin services running on all sharepoint servers.
5) test at least one site collection from each Web app and make sure no issue with that.
6)write some test case from end user stand a point...create a subsite in collection, create a new list, set alerts, test workflow, etc.
7)make sure all services applications you configured are running...from CA browse to services application page and then every service app you configured.
8) if you have a user profile service run full crawl
9) if you have search service, run crawl over here and also test search is working.
10)test each services app you configured.
11)if you have language packs then make sure those are also working.
12) also test the fix which introduced in the CU.
On MSDN there is a nice document, Software updates overview.
Wether you build a new farm or upgrade a farm always review the result documentation created by the proces:
- The (upgrade) log files
- SP2010 Products and Technologie Configuration Wizard (PSconfig.exe) PSCDiagnositics log file
- Central Administration site check update status page
You can use the Test-SPContentDatabase cmdlet to check the status and health of a contentdatabase
Ofcourse validate the end-user experience and validate:
- Verify themes, styles and images
- Verify permissions
- Identify broken links
- Identify broken, missing of hidden Web Parts
- Identify large lists that may be throttled by default
There is no prepared checklist, but from microsoft page of SP2 for SharePoint Server 2010 there is only one known issue :
- After you upgrade the SharePoint Web Front End (WFE) from Windows Server 2008 (R2) to Windows Server 2012, certain SharePoint Designer-customized views that have custom XSL templates may be broken. Moreover, the update can compromise server responsiveness. To resolve this issue, you can install the SharePoint Server update from June 2013 or a later version Cumulative Update (CU) after you upgrade the operating system.
And you can check this post where people found problems during installation of SP2.
You should check grouped list items. SP2 had a problem to display grouped list items. You can find a hotfix for this issue.