It is very important to shutdown Teradata database proper way before power off or restart or shutdown Linux on AWS/Azure/TDVM/Physical System. If you failed to shutdown database proper way then it can lead to many problems including (Teradata, 2017):
Offline Vprocs
Fatal Vprocs
NFR (Node Failure Recovery) nodes automatically starting up similar to HSN (Hot Standby Nodes) on physical systems.
Ghost or phantom nodes joining the database configuration
Data loss / Data Corruption
Billable charges by Teradata to recover data
Process to Shutdown Database Proper Way (Teradata, 2017):
1. Shutdown the database
# /usr/pde/bin/tpareset -x Shutting down Teradata for maintenance
2. Check the database has been shutdown
# pdestate
PDE state: DOWN/HARDSTOP
3. Reboot or Shutdown Linux Machine
# init 6 (For Reboot Linux)
Or
# init 0 (For Shutdown Linux)
4. After Reboot and start Linux reconnect to Teradata with ssh and check to see if database comes up automatically or not
# watch pdestate -a (You are looking for logons enabled) to exit press Control-C or delete key
If the system is stuck at down/hardstop or down/main run this command to bring up Teradata:
# /etc/init.d/tpa start
Monitor the database comes up with logons enabled:
# watch pdestate -a (You are looking for logons enabled)to exit press Control-C or delete key
Teradata. (2017, 08 10). Retrieved from http://knowledge.teradata.com/KCS/id/KCS007365