Six years ago I wrote a short instruction on how to restore OCR and Votedisk in RAC 12c after a diskgroup failure. Yesterday I had a possibility of validating my procedure in 21c RAC environment and it has occurred that it is a bit more complicated. Who would have thought? 21 is just 12 backwards! […]

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RAC 12c

ORACLE RAC 12c: restore OCR and VOTEDISK

Let’s fuckup the cluster! Of course after this operation, the final state of the processes can look like this: The cssd service will not be able to start, because there are no voting disks: OK, so let’s try to stop the cluster services: Now we will have to start CRS in exclusive mode and start […]

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RAC: tips&tricks


In this article I will show how to change IP address of cluster interconnect. First we have to define new address of the cluster interconnect before we change network settings. And now stop all cluster resources on both nodes Now we can change cluster interconnect ips Now we can start init cluster resources on both […]

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RAC: tips&tricks

RAC: change IPs on public network

In this article I will show how to reconfigure IP addresses in public network for RAC. ` First we have to close all cluster resources This command can hang on stopping ASM. It’s normal, because the resource CRSD is using OCR, which is located on ASM diskgroup. In ASM alertlog you will see errors like: […]

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RAC: tpis&tricks

RAC: migrate standalone database to RAC

Procedure to convert a standalone database to RAC 11gR2 I have a single-instance database and I want to convert it to RAC with minimum downtime. The first step is to enable RAC option by recompiling the binaries (YOU HAVE TO STOP THE DATABASE FIRST!!!) After this operation I can startup instance and proceed to migration. […]

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RAC tpis&tricks

RAC: add new node to cluster

Add a new node to RAC Check the network configuration for both nodes On the with active cluster, check the network configuration Configure appropriate network devices on the node, which I want to add Create appropriate user on the new node: Configure shared storage – first install ASMLib drivers (if you are using ASMLib :)) […]

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RAC tips&tricks

RAC: change the voting disk and ocr location

Change VOTE and OCR location First we have to create new ASMLib binding Then we have to create new ASM diskgroup and set the appropriate attributes (at least ‘compatible.asm’) Then we can add a new location for OCR. And remove the old location Now we can replace the voting disk location

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Oracle ASM

There is some kind of wrong understanding, regarding what Oracle ASM really is. A lot of people thinks, that this is some kind of file system, provided by Oracle and that Oracle Database reads data "from ASM", while the truth is, that the database reads data directly from the physical raw device with assistance of […]

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HOWTO: Install Oracle RAC 11gR2 on VirtualBox (OEL6.4)

Install Oracle RAC 11gR2 on VirtualBox: http://www.youtube.com/playlist?list=PLqQNL6H71xCygSF_VqwM8j-Hhft4XoEEx VM templates can be found here: https://mega.co.nz/#!esp1kQQA!CUr8SlErdPppk-GkxedTUAdMpVQPrrrSI3c1ouquAhk Prezi: Route to install simple RAC

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