Amardeep Sidhu's Tech blog

Faced this error while querying v$asm_disk after adding new storage cell IPs to cellip.ora on DB nodes of an existing cluster on Exadata. Query ends with ORA-03113 end-of-file on communication channel and ORA-56841 is reported in $ORA_CRS_HOME/log//diskmon/diskmon.log. Reason in my case was that the new cell was using different subnet for IB. It was pingable from the db nodes but querying v$asm_disk wasn’t working. Changing the subnet for IB on new cell to the one on existing cells fixed the issue. ...

On a T5 Super Cluster (running 11.2.0.3) I was creating a cascaded standby from an already functional standby using RMAN DUPLICATE and it errored out with ORA-01671: control file is a backup, cannot make a standby control file A quick search reveals that it is bug 11715084 that affects most of the 11.x versions except 11.2.0.4. There is a one off patch available for most of the versions or one can install the bundle patch that includes the fix for this patch. I applied BP26 and it worked fine after that. ...

This was my 6th year at Sangam and as always was good fun. We were a group of 4 people who were traveling from Delhi and we reached Hyderabad on Friday morning. Just wanted to keep a day for visiting Ramoji Film City and also wanted to avoid the rush that morning travel on the conference’s starting day brings. So after dropping the luggage at the hotel we hired a taxi and reached Ramoji Film City. It is a huge place and it is tiring to move around checking everything. But fortunately on that day the weather was very pleasant so moving around was good fun. We took a ride what they call as Space Walk and watched few sets where some movies were shot. Also they have a pretty good bird sanctuary over there where they have pretty good number of beautiful birds. Spending time there was nice and fun. ...

A rather not so great post about an ORA-00600 error i faced on a standby database. Environement was 11.2.0.3 on Sun Super Cluster machine. MRP process was hitting ORA-00600 while trying to apply a specific archive log. The error message was something like this MRP0: Background Media Recovery terminated with error 600 Errors in file /u01/app/oracle/product/11.2.0.3/diag/diag/rdbms/xxxprd/xxxprd1/trace/xxxprd1_pr00_6342.trc: ORA-00600: internal error code, arguments: [2619], [539], [], [], [], [], [], [], [], [], [], [] Recovery interrupted! Some googling and MOS searches revealed that the error was due to corrupted archive log file. Recopying the archive file from primary and restarting the recovery resolved the issue. The fist argument of the ORA-600 is actually the sequence no of the archive it is trying to apply. ...

Tim Hall has written some brilliant posts about getting going with writing (blogs, whitepapers etc). This post is the result of inspiration from there only. Tim says that just get started with whatever . If you are into blogging and no so active or even if you aren’t you may want to take a look at all the posts to get some inspiration to document the knowledge you gain on day to day basis. ...

Many people have asked me this question that how they can learn Exadata ? It starts sounding even more difficult as a lot of people don’t have access to Exadata environments. So thought about writing a small post on the same. It actually is not as difficult as it sounds. There are a lot of really good resources available from where you can learn about Exadata architecture and the things that work differently from any non-Exadata platform. You might be able to do lot more RnD if you have got access to an Exadata environment but don’t worry if you haven’t. Without that also there is a lot that you can explore. So here we go: ...

I was troubleshooting some Windows hangs on my Desktop system running Windows 8 and enabled driver verifier. Today when I tried to start VirtualBox it failed with this error message. Failed to load VMMR0.r0 (VERR_LDR_MISMATCH_NATIVE) Most of the online forums were asking to reinstall VirtualBox to fix the issue. But one of the thread mentioned that it was being caused by Windows Driver Verifier. I disabled it, restarted Windows and VirtualBox worked like a charm. Didn’t have time to do more research as i quickly wanted to test something. May be we can skip some particular stuff from Driver Verifier and VirutalBox can then work. ...

Few months ago I contributed a chapter (on Monitoring, Troubleshooting and Performance tuning) to a GoldenGate book on Oracle Press that Robert Freeman was authoring. Thought of posting a small update that the book is now out. My name doesn’t appear on the main page but you will see it in the Acknowledgements section Below is a screenshot taken from Amazon preview . You may want to grab a copy if you are using/planning to use Oracle GoldenGate 11g. ...

So there is a new toy in the market for database geeks : Oracle has released database 12c. Every social platform is abuzz with the 12c activity. So thought that I should also complete the ritual In this post Aman has already summed up many important links. Maria Colgan has posted some useful links here. And here is a link to a slidedeck about Upgrading and Migrating to 12c. Happy 12c’ing !

Yesterday I was configuring EM 12c for a Sun Super Cluster system. There were a total of 4 LDOMs where I needed to deploy the agent (Setup –> Add targets –> Add targets manually). Out of these 4 everything went fine for 2 LDOMs but for the other two it failed with an error message. It didn’t give much details on the EM screen but rather gave a message to try to secure/start the agent manually. When I tried to do that manually the secure agent part worked fine but the start agent command failed with the following error message: ...