Operating system: Sun Solaris 8 Dupler Software: Sun Cluster 3.0 Database: Oracle 8.1.7.3 Fault Phenomenon: 1.oracle Unable to start. 2. Each node or Oracle resource group on all points cannot be started, and it is displayed as OFFLINE. 3. Start Oracle When the Oracle is reported "ORA-01092: Oracle Instance Terminated. Dischanection Forced" error. 4. View $ ORACLE_BASE / Admin / Orcl / BDump / Alert_orcl.log, found with ORA-01534: Rollback Segment Rbsxxx Does Not Exist. Fault Analysis: This fault is caused by the ROLLBACK_SEGMENTS parameter in the initialization parameter file sets a rollback segment that does not exist. Oracle has a concept of rollback rollback segment, which has a very important role in Oracle. Roll Rolling Segments There are two types of public and private, and Oracle's initialization file $ Oracle_base / admin / orcl / pfile / initorcl. ORA has a static initialization parameter Rollback_SEGMENTS. It contains a list of returning segments of the private PRIVATE of ONLINE when Oracle starts. If this parameter sets a rolling segment that does not exist will cause Oracle to report ORA-01534 and ORA-01092 errors when started, eventually lead to the database unable to start, the Oracle resources in the dual-machine will not be ONLINE. If rollback_segments are not specified in the initialization parameters, Oracle will set a part of the PUBLIC's backlink. The number of specific online returns is equal to Transactions / Transactions_Per_Rollback_Segment. Transactions and Transactions_Per_rollback_segment are static initialization parameters in the initialization parameter file. In our OSS system Transactions = 1.1 * (1.1 * processes 5), Transactions_Per_rollback_SEGMENT = 5. Where Processes is also an initialization parameter of Oracle, determine the number of user connections in Oracle, in our OSS system, generally 300. So in our system, if you do not specify rollback_segments, 73 PUBLICs will be returned. Since there is generally not created in our system, we will eventually lead to all public returning segments online. Troubleshooting: You can comment out of the ROLLBACK_SEGMENTS in the Oracle Initialization Parameters and restart the database. If it is dual-machine, you want to change the initialization parameters of Rollback_Segments simultaneously on both nodes. Daily maintenance: 1. It is best to maintain the use of VI commands when the initialization parameter file is maintained; or use the ASCII mode to the local, use Utlraedi to modify the ASCII mode FTP to the host system. Don't use a copy screen to the host to copy the initialization parameters to the local, because the parameters of Rollback_Segments are very long, and this parameter branch will be copied. 2. Initialization parameters in the system of the two machine must be synchronized. 3. If you comment out of the ROLLBACK_SEGMENTS parameter, the system will only turn the PUBLIC's backlite, so if the public return segment created in the system is rare, the Oracle will only have little rollback segments in the system after the system starts. This will seriously affect the performance of the system. So if you want to comment about the Rollback_SEGMENTS parameter, it is recommended to recreate all the rollback segments to the public manner.
