First login to <sid>adm user of hana database
su - <sid>adm
Execute the below command
HDB start
This executes the HDB program in path /usr/sap/<SID>/HDB<instance no.>/
The below command for stopping also uses same HDB program
HDB stop
One more program that can be used for start/stop of Hana DB is the sapcontrol program located in the path /usr/sap/hostctrl/exe/
The start command is as follows
sapcontrol -nr <instance no.> -function Start
The stop command is as given below
sapcontrol -nr <instance no.> -function Stop