Universal Unique Identifier (UUID) error during 12c RAC Installation

During installation of 12.1.0.1 (12c) grid infrastructure (RAC or standalone), prerequisite check screen may show a warning for “Device Checks for ASM”, stating:
Cannot verify the shared state for device /dev/oracleasm/disk/<ASM Disk> due to Universally Unique Identifiers (UUIDs) not being found, o

Performing Block Media Recovery

While running SQL statements on the database, suddenly SQLs may start failing with error messages showing that there is database block corruption in some datafile(s). Error messages in the Alert Log could be similar to the following.

... ORA-01578: ORACLE data block corrupted (file # 4, block # 36321)

Installing Oracle 12c Release 1 RAC on Linux 6

This article explains how to install a 2 nodes Oracle 12c release 1 Real Application Cluster (RAC) on Oracle Linux 6. I did this installation on Oracle Virtual Box by creating 2 virtual machines with shared storage. OS platform I used is Oracle Enterprise Linux 6 (update 3), and Oracle GI and RDBMS version is 12.1.0.2. Same installation guide should work for Redhat Linux 6 also

Creating Virtual Machine using Oracle Virtual Box

DBAs can use Oracle Virtual Box to create virtual machines for testing purposes. Even Oracle RAC installation practice can be done using virtual machines by creating virtual shared storage for the virtual RAC nodes.

Following are the steps with screen shots for how to create a virtual machine using Oracle

Installing Oracle Linux 6 for DBAs

Being a DBA, it is good to be independent of system admin as much as you can because many times you could be in a situation where you need to install and/or manage the OS yourself and also need to suggest some OS tuning or parameter setting to run Oracle successfully on your system. Here I will be explaining how to install Oracle Linux 6 on a server

ORA-01653: unable to extend table by 8192 in tablespace

ORA-01653: unable to extend table <SCHEMA_NAME>.<SEGMENT_NAME> by 8192 in tablespace <TABLESPACE_NAME>

This error is quite common and it clearly means oracle was not able to allocate space to a segment and returned this error. Alert log file will show error similar to the following.

Wed May 31 17:15:28 2013 ORA-1653: unable to extend table SCOTT.TEST by 8192 in tablespace DATA_TBS

Creating Shared Disks for Oracle RAC on Oracle Virtual Box

If you want to do a test Oracle RAC (12c R1, 12c R2) installation on virtual machines you would need to create shared disks to be used across all the RAC nodes to store OCR/voteDisk and other ASM disks for database storage.
In the following, I will explain how we can created shared disks in Oracle Virtual Box.

Installing Oracle 12c Release 1 RAC on Linux 7

This article explains how to install a 2 nodes Oracle 12cR1 Real Application Cluster (RAC) on Oracle Linux 7. I did this installation on Oracle Virtual Box by creating 2 virtual machines with shared storage. OS platform I used is Oracle Enterprise Linux 7 (update 1), and Oracle GI and RDBMS version is 12.1.0.2. Same installation guide should work for Redhat Linux 7 also.

Configuring SSH for Oracle RAC installation

User equivalence is required on all nodes during Oracle RAC installation which provides OUI to log into all remote notes to perform copy/install the software and perform other configuration tasks. We can use different approaches to setup the passwordless ssh connectivity.

Using Cluster Verification Utility (cluvfy)

While installing RAC, cluster verification utility (cluvfy) is used to check whether all required prerequisites have been met, before proceeding to the Grid Infrastructure for RAC installation. 

We also use it after the installation to check if everything is working fine after the installation.