Oracle Multitenant and custom DBCA templates

Today I’ve encountered an annoying issue while adapting a few scripts for automatic database creation. I track it here so hopefully it may save a few hours of troubleshooting to someone…

I’ve used the DBCA to prepare a new template:


Then continued by customizing other options, including init parameters and datafile/logfile paths. Finally, I’ve saved it as a new template instead of creating the database.

I’ve checked the resulting .dbc and seen that there was, as expected, the parameter “enable_pluggable_database”=”true”.

Then I’ve moved the template file to my $HOME directory and tested the silent database creation with the option “-createAsContainerDatabase true”:

The database configuration has completed successfully, without errors. I’ve accessed my new container, and I’ve been surprised by seing:

In fact, there were no pdb$seed datafiles:

After little investigation, I’ve found these lines in the dbca trace.log:


Then I’ve struggled with dbca and templates a few times before finding that, actually, the magic “enable pluggable database” is done by dbca only if the template file name is not customized.

Running the same exact command with the very same template file but renamed to $ORACLE_HOME/assistants/dbca/templates/General_Purpose.dbc actually works (notice the diff at the first line):



I’ve also tried to cheat and use a symlink to my previous custom template, and surprisingly, it still works:

In the dbca trace log the message saying that the DB will be NON-CDB disappears:

So the problem is really caused by the different filename/location of the template.

IMHO it’s a kind of bug, the decision between a CDB and NON-CDB should not be taken by DBCA.  Moreover, it’s not based on the content of the template, which would be logic. But today I’m late and lazy, I will not open a SR for this.


RAC Attack 12c at Collaborate 14 and advanced labs

I’ve just published an advanced lab on SlideShare that RAC Attack attendees may do at Collaborate this year, instead of just doing the basic 2-node RAC installation on their laptop.

We’ll offer also an advanced lab about Flex Clusters and Flex ASM (written by Maaz Anjum). Moreover, I’m working on an additional lab that allows to implement a multi-node RAC by using Virtual Box linked clones and GI Home clones like I’ve shown in my previous post.

RAC Attack at #C14LV will be like fun again. We’ll have a few t-shirts for the attendants, designed by me and Chet “Oraclenerd” Justice, kindly sponsored by OTN.

The workshop will end up with beers and snaks (again, thank you OTN for sponsoring this :-)).



If you’re planning to attend Collaborate, join us and start your conference week in a good mood 🙂


Multinode RAC 12c cluster on VirtualBox using linked clones

Recently I’ve had to install a four-node RAC cluster on my laptop in order to do some tests. I have found an “easy” (well, easy, it depends), fast and space-efficient way to do it so I would like to track it down.

The quick step list

  • Install the OS on the first node
  • Add the shared disks
  • Install the clusterware in RAC mode on on the first node only
  • Remove temporarily the shared disks
  • Clone the server as linked clone as many times as you want
  • Reconfigure the new nodes with the new ip and naming
  • Add back the shared disks on the first node and on all other nodes
  • Clone the GI + database homes in order to add them to the cluster

Using this method the Oracle binaries (the most space consuming portion of the RAC installation) are installed and allocated on the first node only.

The long step list

Actually you can follow many instruction steps from the RAC Attack 12c book.

  • Review the HW requirements  but let at least 3Gb RAM for each guest + 2Gb more for your host (you may try with less RAM but everything will slow down).
  • Download all the SW components , additionally you may download the latest PSU ( from MOS.
  • Prepare the host and install linux on the first node. When configuring the OS, make sure you enter all the required IP addresses for the additional nodes. RAC Attack has two nodes collabn1, collabn2. Add as many nodes as you want to configure. As example, the DNS config may have four nodes

At this point, the procedure starts differing from the RAC Attack book.

  •  Go to the VirtualBox VM settings and delete all the shared disks2014_03_16_22_05_26_Oracle_VM_VirtualBox_Manager
  •  Clone the first server as linked clone (right-click, clone, choose the name, flag “Linked Clone” as many times as the number of additional servers you want.

2014-03-16 22_09_42-Clone Virtual Machine


  • By using this method  the new servers will use the same virtual disk file of the first server and a second file will be used to track the differences. This will save a lot of space on the disk.
  • Add back the shared disks to all the servers.
  • Start the other nodes and configure them following the RAC Attack instructions again.
  • Once all the nodes are configured, the GI installation has to be cleaned out on all the cloned servers using these guidelines:

  • Then, on each cloned server, run the perl as follows to clone the GI home, but change the LOCAL_NODE accordingly (note: the GI Home name must be identical to the one specified in the original installation!):

  •  Then, on the first node (that you have started and you have reactivated the clusterware stack on it with crsctl enable crs / crsctl start crs ;-)), run this command to add the new nodes in the definition of the cluster:


  • from the first server copy these files on all the other nodes:

  •  Then clone also the DB Home (again, run it on each new server and specify the same DB home name that you have used in the original installation):

  •  On each new node run also the updatenodelist and the DB command to update the node list for the DB home:

  •  and finally, run the GI on each new node to finalize their inclusion in the cluster!! 🙂


  • As result, you should be able to seen all the cluster resources started correctly on all the nodes.


I know it seems a little complex, but if you have several nodes this is dramatically faster than the standard installation and also the space used is reduced. This is good if you have invested in a high-performance but low-capacity SSD disk like I did :-(.

Hope it helps, I paste here the official documentation links that I’ve used to clone the installations. The other steps are my own work.