SharePoint Products and Technologies Pre-Upgrade

If the following error is detected by the preupgradecheck process:
Failed : Pending upgrade operation detected in this farm
Running SharePoint Products and Technologies Configuration Wizard may not work. You may have to use the following script:

psconfig -cmd upgrade -inplace b2b -wait

This should solve the problem.

Clearing Transactional Log File

The transaction log for database 'DatabaseName' is full. To find out why space in the log cannot be reused, see the log_reuse_wait_desc column in sys.databases:
Use the following db scripts to clear the log:
use DBName
dbcc shrinkfile(2,2048)

Sharepoint 2010 Move-SPSite Issues

Recently in one of the sharepoint migration projects I had a requirement to move all the contents of a sitecollection to a seprate content database. I was using Move-SPSite powesrshell comment and when I executed this command I got error message: Operation is not valid due to the current state of the object. In the eventviewer the error logged was : Database 'WSS_Content_80_Demo' on SQL Server instance 'XXXX' is not empty and does not match current database schema.
After spending sometime searching for the he problem I found that the Content DBs were out of sync. Then I executed the following command:
PSConfig.exe -cmd upgrade -inplace b2b -force -cmd applicationcontent -install -cmd installfeatures