simple note for exchange 2013 cu upgrade

1. download exchange 2013 cu from microsoft and extract
2. upgrade windows ad schema
    setup.exe /PrepareSchema /IAcceptExchangeServerLicenseTerms
    setup.exe /PrepareAD /IAcceptExchangeServerLicenseTerms
    setup.exe /PrepareDomain /IAcceptExchangeServerLicenseTerms
3. upgrade cu on front end server & reboot
4. upgrade cu on dag server
    move-activemailboxdatabase -server notupgradenow
    suspend db replication on ecp
    upgrade cu & reboot
5. resume db replication on ecp
6. move-activemailboxdatabase -server notupgrade now
    suspend db replication on ecp
    upgrade cu & reboot
7. resume db replication on ecp