Cannot Auto Extend (CannotExtend)

Displays whether a segment in an autoextensible tablespace cannot extend due to a lack of operating system space or reaching the maximum space on the tablespace.

This parameter monitors only autoextensible tablespaces and tablespaces with an allocation type UNIFORM. If a non-autoextensible tablespace cannot extend, the Free-Space-Deficit-FreeSpaceDeficit parameter goes into alarm. 

Only permanent tablespaces are monitored by this parameter. To monitor temporary tablespaces, you must use Smallest-Free-Space-Available-in-Temporary-Tablespaces-TempTSLeft and Smallest-Free-Space-Available-in-Temporary-Tablespaces-TempTSLeftPct.

We use the following pconfig variable to set the minimum size left until we consider the tablespace cannot be extend.

/OracleConfig.{sid}.cannotExtMaxFreeBytes

If this parameter is not set the default value is 1024*1024, which equals 1MB.

Recommendations

The parameter alerts only if there is no space available for the tablespace to allocate the next extent. In order to get a proactive monitoring notification and alerts before an ORA error occurs, see ETSM (ORACLE_ETSM).

If the tablespace can no longer extend due to a lack of operating system space, delete or move error log files, archive files, or any unnecessary files.

If the tablespace can no longer extend due to reaching the maximum space in the tablespace, increase the space in the tablespace.

BMC PATROL properties

BMC ProactiveNet Performance Management properties