I am using RS.exe to migrate all SSRS content from one server (SQL Server 2008) to another (SQL 2012). It is moving everything in a mixed order which is causing items to be not migrated. Eg a Report is migrated before the dataset or datasource. A report in a subfolder is migrated before the sub folder is created which triggers an error.
rs.exe -i ssrs_migration.rss -e Mgmt2010 -s http://OLDSERVER/ReportServer -u USERNAME -p PASSWORD -v ts="http://NEWSERVER/ReportServer" -v tu="USERNAME" -v tp="PASSWORD"
-v security="True" > e:\rs.exe\rs_output.txt
All content should be migrated but its not due to sub folders missing which means the report / datasource etc can't be copied across. It also means reports are not linked to a datasource as they were copied over after the report.