Hotfix installation on SharePoint 2010 farm?

Question

We are going to install the hotfix - http://support.microsoft.com/kb/2553031, would like to clarify few points.

1. does the SharePoint & IIS services need to be stopped before installing?
2. do need to follow any sequence like start with CA server, index, query, app & WFEs?
3. shall we run parallelly on the servers?
4. do we need to run the configuration wizard on the servers in the same sequence?
5. does the system reboot required?
6. does it change the DB schema?
7. how to rollback if it does not installed successfully?
8. is there any known issue with this hotfix?

Answer 1

1) No
2) No
3) Sure
4) No
5) Possibly
6) Yes
7) Rebuild farm and restore from backup (you did back up before installing, right?)
8) Go straight to the December CU instead

Answer 2

To address point 7 specifically, if your entire farm is virtualized as most are these days then you can simply take snapshots of the VMs prior to applying the patch. Naturally, you should also have full SQL Backups as well, just in case.

Also, you should apply the patch to a dev or QA farm prior to applying it to production. Not only does this give you a chance to test the patch, but it also would would answer most of the questions you list.