Checks to be performed before shutting down

Now that we learnt in how to start and stop the SAP systems .There are few checks that we need to do before doing a system shutdown and there are few functionality checks to be done after system start that is explained as below .

SHUTDOWN OF SAP SYSTEMS :-

• The SAP system may need to be stopped due to maintenance purposes.
• These include activities such as : 
• Taking an offline database backup
• Upgrading the SAP kernel
• Activation of modified profile parameters
• Upgrade of the SAP instance
• Restarting due to system performance issues

Sequence of Stopping an SAP system

• Stop all Dialog Instances one by one (there is no sequence to be followed here)
• Stop the Central Instance
• Stop the Central Services Instance if it is on a separate host other than the Central Instance
• Finally , Stop the Database Instance

Checks to be performed before shutting down

• Check transaction SM04 to find out if users are active.

• It is a best practice to post a message on the SAP system informing the active users about the decision to shut down the system.
• You can create a system message using transaction SM02
• To check for all users across all instances , whether it be central or dialog , use the global command AL08,SM04 command will show only the users logged onto the particular dialog instance.
  
• Check SM50 if there are no critical background jobs running before shutdown.If there are such jobs , identify the job owner and inform them about the shutdown reasons.Also plan to restart the jobs after the system is up and running.
• 
• Transaction SM66 is the correct transaction to use , for viewing processes running for different dialog instances. viewing processes running for different dialog instances
• Check using SM37 , for released , ready and active jobs.
• During the course of shutdown , the active and just released jobs might fail , and cause inconsistencies in transaction processing.If so , speak to the Job owner and ask them to reschedule the jobs or cancel the active ones
• Check for Updates – SM13
• It is important to check if there are any open updates pending
• If there are any open updates , check the logs and trace files to identify the reason for the delay. In many cases , the updates may be pending because of excessive database activities.
• Before deleting any open update , always check the SQL analysis transaction ST04.
• Check Batch Inputs – SM35
• Batch inputs are sessions which are recorded by users and can contain a sequence of reports and transactions where certain data is entered.This session is periodically run depending on the business need.Make sure that there are no active batch inputs during shutdown
• Check for outbound and inbound queues in transaction SMQ1 and SMQ2 .So that failed queues can either be saved or executed again if after system restart that does not happen automatically via the SMQS scheduler.