ORACLE DBA

Recovery of  Block Corruption by using  RMAN  For this we need to simmulate the issue in TEST DB 1) in our case take emp table which is already existed under scott schema and the default tablespace is users 2) try to access the emp table select count(*) from scott.emp;  check segemnt header block number SQL> col SEGMENT_NAME for a20 SQL> select segment_name,header_block,owner from dba_segments where segment_name='EMP' SEGMENT_NAME         HEADER_BLOCK OWNER -------------------- ------------ ------------------------------ EMP                           146 SCOTT 3) OS level check datafile status using db verify tool. oracle@localhost.localdomain:/home/oracle [TESTDB] >dbv file=/u01/app/oracle/oradata/TESTDB/users01.dbf DBVERIFY: Release 11.2.0.3.0 - Production on Wed Jul 5 23:09:35 2017 Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved. DBVERIFY - Verification starting : FILE = /u01/app/oracle/oradata/TESTDB/users01.dbf

What is the Cluster Health Monitor? The Cluster Health Monitor collects OS statistics (system metrics) such as memory and swap space usage, processes, IO usage, and network related data. The Cluster Health Monitor collects information in real time and usually once a second. The Cluster Health Monitor collects OS statistics using OS API to gain performance and reduce the CPU usage overhead. The Cluster Health Monitor collects as much of system metrics and data as feasible that is restricted by the acceptable level of resource consumption by the tool. What is the purpose of the Cluster Health Monitor? The Cluster Health Monitor is developed to provide system metrics and data for troubleshooting many different types of problems such as node reboot and hang, instance eviction and hang, severe performance degradation, and any other problems that need the system metrics and data. By monitoring the data constantly, users can use the Cluster Health Monitor detect potential problem ar

11G R2 RAC: gPnPPROFILE In this post, I will explain what is gPnPprofile, what does it contain and how is it used by clusterware. WHAT IS gPnPPROFILE? The gPnPprofile is a small XML file located in GRID_HOME/gpnp/ /profiles/peer under the name profile.xml. It is used to establish the correct global personality of a node. Each node maintains a local copy of the gPnPProfile and is maintanied by the gPnPDeamon (GPnPD) . WHAT DOES gPnPPROFILE CONTAIN? gPnPProfile  is used to store necessary information required for the startup of Oracle Clusterware like  SPFILE location,ASM DiskString  etc. It contains various attributes defining node personality. ==> Cluster name ==> Network classifications (Public/Private) ==> Storage to be used for CSS ==> Storage to be used for ASM : SPFILE location,ASM DiskString  etc ==> Digital signature information : The profile is security sensitive. It might identify the storage to be used as the root partition of a machine.  Hence, it