Steps to follow when upgrading SharePoint 2007 Server Farm from SP1 to SP2

A few days back we started the upgradtion process of one of our clients SharePoint 2007 server farm from Service Pack 1 to Service Pack 2. After studiyng a lot, discussing with Microsoft Support Team, we have summarized the steps and best practices that needed to be followed and they are listed below:

1. FULL SQL Backup for all SharePoint related DBs (from SQL server -> management studio->Databases->backup)

2. Run PREPARETOMOVE stsadm command on all content DB
http://technet.microsoft.com/en-us/library/cc262122(office.12).aspx

syntax: stsadm -o preparetomove -contentdb

3. Screenshot of the Central administration site ->content dbs -> with all sites in it.

4. Detach all content DB from WebApp (only the end user web application , not for SSP ,mysite ,search etc)
http://technet.microsoft.com/en-us/library/cc287664(office.12).aspx

5. Backup all your customizations (from file system including the custom solutions and web.config files from all the servers in farm)

6. Install WSS x64/86 SP2 Binaries on all servers
http://www.microsoft.com/downloads/details.aspx?FamilyId=79BADA82-C13F-44C1-BDC1-D0447337051B&displaylang=en

7. Install MOSS x64/86 SP2 Binaries on all servers
http://www.microsoft.com/downloads/details.aspx?familyid=B7816D90-5FC6-4347-89B0-A80DEB27A082&displaylang=en

8. Run the SharePoint Configuration wizard (SCW) on application server that runs the SharePoint Central Admin

9. Run SCW on all other SharePoint server in farm

10. Attach all content DB to respective Web Applications as per the screenshot taken at step 3
http://technet.microsoft.com/en-us/library/cc288692(office.12).aspx

11. Logon to Central Admin and check farm version 12.0.0.6421 (operations->servers in farm)