No Applications Can Run ("Frozen" System)

At times you may find that your system has completely frozen. No application can proceed, unlike a slow running system. If this happens, it will usually happen abruptly. It is often the result of a resource being completely depleted, and the Oracle database system can no longer continue.

The most common reasons for a frozen system are:

The archiving of offline redo log files (that is, the copying of online redo log files to the archiving directory by the Oracle background process ARCH) has frozen. SAP databases in production run in ARCHIVELOG mode. This means that an online redo log file can only be overwritten with information from the redo log buffer by the log writer (LGWR) when its contents have been archived. If archiving is not possible, the database system cannot continue.
Check whether the ARCH process is running (LOG_ARCHIVE_START (Oracle)). Check whether the archiving directory is full (Archive Stuck). For more information on how to do this, see Showing Instance Status with BR*Tools.

You should monitor the archiving process on a regular basis to avoid the freezing of the system due to errors in this area. You can use the options provided by CCMS, as described in Displaying Logs for Redo Log Backups (Oracle).

For more information on how to change ARCHIVELOG mode, see Altering the Database Instance with BR*Tools.
All SAP processes are locked.