Beyond the Box

How to Clone an Oracle Server VM on VMWare vSphere ESXi

After having performed this operation a number of times I now feel I'm ready to blog on the topic. Thanks goes to all those who have posted on this topic before me.

In this post I refer to the server that you are copying as the 'Source', and the new server as the 'Clone'.

(Also note that I am obviously working in a Windows environment.)

Step 1: Clone the VM  

The easiest way to do this with an ESXi host is to shutdown the source server and copy the .vmx and .vmdk files using the 'Browse Datastore' dialog in vSphere Client.

In vSpehere Client, select root node on left, go to 'Configuration' tab, select 'Storage', right-click on Datastore and select 'Browse Datastore…'

1. Shutdown the source VM
2. Copy the .vmx file and all .vmdk files.
3. Create a new folder.
4. Paste in the copied files.
5. Right-click on the pasted .vmx file and select 'Add to Inventory…'  

Step 2: Startup the Clone (but keep the Source server off)  

Startup the Clone server and when vSphere Client prompts, select 'I copied it'.

Step 3: Uninstall Enterprise Manager Console

emca -deconfig dbcontrol db -repos drop

Make sure you run this as a user that is a member of the local group ora_dba.

Step 4: Edit listener.ora  

Change occurrences of the old hostname in listener.ora to the intended new hostname. You might like to update tnsnames.ora now too.  

Step 5: Disconnect the Clone's network interface  

The servers that I have been cloning are joined to a domain, so if your server is not an Active Directory member, you can skip this step.

Disconnecting from the network ensures that the disjoin operation in Windows doesn't delete the Source server's computer account from Active Directory.

In vSphere Client click on 'Edit virtual machine settings' select the network adapter and untick 'Connected'.

Step 6: Rename and Restart  

Change the hostname in Windows, but regardless of whether you intend this machine to join a domain, for now choose the 'Workgroup' option.

 

Step 7: Re-connect Network and Join Domain

If you skipped step 5, then you can skip this step too.

Edit the virtual machine settings and reconnect the network.

Once the network is connected, open the Computer Name dialog in Windows again and this time choose the domain option. Provide your AD credentials to join the server and restart when prompted.

Step 8: Re-install Oracle Enterprise Manager

I've never had any luck re-installing EM using the command line, so my recommendation is to use the Oracle 'Database Configuration Assistant' tool. Note '…Step 1 of 6…' in the dialog title:

If step 3 was successful, you should see Step 3 of 6 in the DBCA tool as follows.

Ensure 'Configure Enterprise Manager' is ticked (it might be already), and proceed to the end of the tool to complete the install.

That's it – you should now a functioning clone server with an updated shortcut in the start menu to Oracle Enterprise Manager.

Cloning VMWare Virtual Machines the right way

As consultants we must stay current on wide range of the Autodesk products that are available. When delivering a customised piece of software we ensure that it works in the latest and previous version (sometimes two previous versions) of Autodesk products (eg. AutoCAD 2012, AutoCAD 2013) and in few other Autodesk products as well (eg. AutoCAD Map 3D and Civil 3D).

We use virtual machines (VMs) to setup our test environment and we tend to clone an existing VM and customise it, based on our project requirements. When cloning an existing VM server, a small glitch ocurs: when an existing server "ABC" is cloned to a new server "XYZ", the existing server is disconnected from the Active Directory Domain, which creates a hassle for users of the existing, working system.

This is because certain machine attributes (such as SID, MAC Address and IP address) that are used as a means of identifying the machine on the network should be unique. Having two machines that are completely identical will cause an Active Directory disjoin or more generally, a network conflict. Successfully duplicating a virtual machine requires removing any attributes that are unique.

The SYSPREP utility prepares the server for duplication, which means that it removes the server's SID and other attributes that are unique.

Before you perform the clone, run sysprep on the machine to be cloned.  "C:\windows\System32\sysprep\sysprep.exe"

Tick the 'Generalise' option so that a new SID is created for the machine, which will ensure the clone is unique.