Shutting down the SP Servers (FARM)
1. WFE Servers
2. Index and Search Servers
3. App Servers (the App server that runs Central Administration web site last)
4. SQL Servers
Turning on the SP Servers (FARM)
[we can use the below hierarchy for re-boot also]
1. SQL Servers
2. App Servers (the App server that runs Central Administration web site first)
3. Index and Search Servers
4. WFE Servers
1. SQL Servers
2. App Servers (the App server that runs Central Administration web site first)
3. Index and Search Servers
4. WFE Servers