Deactivating and Reactivating Updating 
The SAP system stops updating automatically if a fatal database error occurs. Serious database errors require action on the part of the database administrator. The automatic update stop prevents updates from being processed and terminating abnormally because of a database problem. This in turn makes clean-up in the update system easier after the problem has been resolved.
If you notice a problem that will affect updating, you can also deactivate updating manually. For example, if you see that free space in the database is critically low, then you can stop the update before the database problem starts to cause update errors.
The procedure for deactivating and reactivating updating manually are described below.
Caution
Deactivating updating is an emergency measure. It suspends all user transactions in the SAP system until update is reactivated.
Deactivate updating only if you are sure that a system-wide problem exists and the problem will cause many or all updates to terminate prematurely.
Prerequisites
If you can answer any of the following questions in the affirmative, you can manually stop the update if it has not already been automatically stopped.
Has an update problem just been notified to you by the alert monitor? Does it affect all updates?
Or do you see a system-wide problem occuring, such as a warning from the alert monitor about a serious database problem?
Procedure
Start Update System Administration. To do this, choose
Tools 
Administration Monitor Update 
. Alternatively enter transaction code SM13.Check whether updating is active. One of the following messages is output at the bottom of the initial screen of the update system:
Update is active
Update is inactive
If updating is active, deactivate it. Choose
(Administration), and in the Status line Updating is active choose the Deactivate button.The status message changes. You and all other SAP users are notifed of the deactivation.
Once the underlying problem has been fixed, reactivate updating. Proceed in the same way as for deactivation, and then choose Activate.
Note
You can also deactivate and reactivate updating in update management (transaction SM14).
Result
Deactivating update causes all active transactions in your system to pause. Users cannot create updates during this pause. They can only continue working once updating is reactivated.
Background processing jobs are also automatically paused.
If it is not necessary to restart the SAP system; users can resume their work without loss of data after update reactivation. The processsing of paused jobs also continues when you reactivate updating.
A message announcing the pause in activity appears on every terminal in the SAPGUI status line.