Database migration across platforms and conversion of single instance to RAC

Working in a huge RAC environment, each passing day is a learning day for me. After setting up 4 node RAC on HP UX Itanium 2 Severs, the subsequent task/challenge is to migrate single instance databases (around 16) from AIX OS to HP OS and plus converting single instance to RAC.

I have started this task on a low confidence note, I would be lying if I say I was very much confident. However, as thing progress, my confidence level went high and at the end I have successfully migrated a database (single instance) from AIX OS to HP OS and then converted the single instance database to RAC database.

To give you a rough idea what I have done:

Converted database from AIX to HP using RMAN.
On HP, then, converted this databases from single-instance to RAC database. There are few ways using which you can achieve this. However, I have opted the DBCA option to execute the task.

Next step is to migrate and convert the rest of the databases using the same method.

Happy reading,

Jaffar

Oracle doesn't allow replacing ocr disk or adding the mirror copy if the new disk size is less than the existing ocr disk size

At least my self now decided not to believe in the ML Notes (not always though), its better testing what they have said. I was trying to replace an existing ocr location and also trying to add mirror copy of ocr. During RAC setup, we have used 1gb disks for OCR and voting disk (with single copy of each).
In order to multiplex the OCR and Voting disk we have requsted our UNXI team to gives us the four raw disks with 500mb each (oracle recommends 300MB for OCR/Voting Disk, may be less) and whil trying to replace/mirror the ocr to the new raw disks, I have got the following errors:

for OCR Mirror copy: PROT-22:Storage is too small
for replace OCR : PROT-16: Internal Error

As usaul, we search in the ML and found couple of notes for the same errors (317628.1 & 444757.1). Well, the ML Note : 317628.1 said the following:

" fails with "PROT-22: Storage too small" error. The problem is due to an Oracle bug where this operation requires the OCR mirror partition/file tobe larger than the original by up to 128MB. The bug has been fixed in the 10.2.0.2 patchset."

The note says that this bug has been fixed in 10.2.0.2 patch, we are on 10.2.0.3 patch and the bug still persists.

Happy reading,

Jaffar

A stupid and silly issue took hours to resolve

This morning we were trying to create a RAC database using the dbca utility on HP UX Itanium II servers and a silly/stupid error keep coming for a long time and we got strucked for good amount of time.

The error message which was coming 'Unable to copy the '/etc/oratab' to '/tmp/oratab.' and when ignore option was choosen from the error screen, the subsequent message was 'Encountered file error when copying listeners from home=$ORACLE_HOME/asm".

We certainly knew that the issue is either with the permission or copying the said file and our immediate step was checking the permisson and ownership on the oratab file. Everything was just fine and then we try to create a file in the /tmp directory using touch command from the Oracle user and it worked without any hassles.

We were able to create the RAC database successfully on a single node and when tried to add instance on the other node, the same issue encountered again and again.

We finally thought of running the dbca in tracing mode and when the same problem arises and when we had a look at the trace file, we couldn't stop wondering about the silly/stupid thing which Oracle was complaining.

The trace file reveals that it is looking for 'scp' executable in '/usr/local/bin' location, whereas, the 'scp' excutable was in '/usr/bin' directory. We simply created a link for 'scp' in the '/usr/local/bin' and dbca run smoothly and we were able to complete the RAC database creation.

Past three months, its been really a great working expeirence on RAC and I must say, we have faced hell a lot of issues while trying to implement RAC on HP Virtual Machines. Definately, its a great learning phase.

Guess what's next? MOVING 8 DEVELOPMENT DATABASE TO RAC from AIX to HP. Umm.. a good and taugh task ahead.

I will keep posting my experience and the issues that have faced while setting up our 16 node RAC with 8 databases.

Happy reading,

Jaffar