Exalogic Virtual Tea Break Snippets - Cloning an existing vServer

Following on from my Blog entry "Scripted Template Generation from an existing vServer" I have built a wrapper script that can be used to execute the Template Generation script or Clone a specific vServer. This script was not incorporated into the original script because it must be executed on a Compute Node with access to the /OVS/Repositories directory and the Compute Node are a minimal install and hence do not have all the required software available. As part of the Cloning process this new script will create an Assets input file that can be used with the CreateAssets.sh describe in the blog "Scripting Asset Creation" and optionally execute the result to create the clone.

Exalogic Virtual Tea Break Snippets - Scripted Template Generation from an existing vServer

As part of your Exalogic Virtual environment you may want to build vServer that will be used, going forwards, as a template for future vServers. Currently the "Exalogic Elastic Cloud Administrator's Guide" has an appendix describing how this can be achieved using the OVMM interface. Based on internal A-Team work it is now possible to achieve this directly from a compute nodes command-line without accessing OVMM.

As a result of this I have built the script below that will take the files associated with a "Stopped" vServer and converts them to a template.

For this templating process to work the script will need to be executed on a machine with access to the /OVS/Repositories/* directories and this means running directly on one of the Compute Nodes (I generally run it on Compute Node 1).

Because of the space and resource limitations of the Compute Node (minimal OS) we will need to create a and mount a Share from the internal ZFS to save the working files and ultimately the Template. To this end the script will take a number of parameters that will specification of these directories. If these are not specified the script assumes we have the ZFS /export/common/images mounted on /u01/common/images.

As can been seen from the Usage section below the script only mandates the Name of the vServer to be copied but assumes that the user has stopped the vServer previously. Once the template has been created, or post copy, the vServer can be restarted.

Exalogic Virtual Tea Break Snippets - Some Simple ZFS Scripts

Whilst working on an Exalogic Upgrade I was working with the ZFS storage and having executed the same commands a number of times I decided to script them. This short blog entry, although it will grow over time, contains the scripts I find useful. For each of the scripts I will simply provide a brief description and the source of the script and occasionally add the output assuming it is not too long. Where I need to pass the Hostname / IP Address of the storage heads the scripts will use the flags:

• -p <Primary - first storage head>
• -s <Secondary - Second storage head>

I will be using a combinations of simple bash scripts and the more function ZFS scripting language.

Exalogic Virtual Tea Break Snippets - Creating a ModifyJeOS VirtualBox

Following on from my previous blog entry "Modifying the Base Template" I decided to put together a quick blog to show how to create a small VirtualBox, guest, that can be used to execute the ModifyJeOS and hence edit you templates. One of the main advantages of this is that Templates can be created away from the Exalogic Environment. For the Guest OS I chose Oracle Linux 6u3 and decided to create it as a basic server because I did not require a graphical interface but it's a simple change to create it with a GUI.

Required Software

• Virtual Box.
• Oracle Linux.

Exalogic Virtual Tea Break Snippets - Modifying the Default Shipped (Base) Template

Having installed your Exalogic Virtual environment by default you have a single template which can be used to create your vServers. Although this template is suitable for creating simple test or development vServers it is recommended that you look at creating your own custom vServers that match the environment you wish to build and deploy. Therefore this Tea Time Snippet will take you through the simple process of modifying the standard template.

Exalogic Virtual Tea Break Snippets - Creating and using Distribution Groups

By default running your Exalogic in a Virtual provides you with, what to Cloud Users, is a single large resource and they can just create vServers and not care about how they are laid down on the the underlying infrastructure. All the Cloud Users will know is that they can create vServers. For example if we have a Quarter Rack (8 Nodes) and our Cloud User creates 8 vServers those 8 vServers may run on 8 distinct nodes or may all run on the same node.

Although in many cases we, as Cloud Users, may not be to worried how the Virtualisation Algorithm decides where to place our vServers there are cases where it is extremely important that vServers run on distinct physical compute nodes. For example if we have a Weblogic Cluster we will want the Servers with in the cluster to run on distinct physical node to cover for the situation where one physical node is lost.

To achieve this the Exalogic Virtualised implementation provides Distribution Groups that define and anti-aliasing policy that the underlying Virtualisation Algorithm will take into account when placing vServers.

It should be noted that Distribution Groups must be created before you create vServers because a vServer can only be added to a Distribution Group at creation time.

Exalogic Virtual Tea Break Snippets - Scripting Asset Creation

So far in this series we have looked at creating asset within the EMOC BUI but the Exalogic 2.0.1 installation also provide the Iaas cli as an alternative to most of the common functionality available within EMOC. The IaaS cli interface provides access to the functions that are available to a user logged into the BUI with the CloudUser Role.

As such not all functionality is available from the command line interface however having said that the IaaS cli provides all the functionality required to create the Assets within a specific Account (Tenure). Because these action are common and repeatable I decided to wrap the functionality within a simple script that takes a simple input file and creates the Asset.

Following the Script through will show us the required steps needed to create the various Assets within an Account and hence I will work through the various functions within the script below describing the steps.

You will note from the various steps within the script that it is designed to pause between actions allowing the proceeding action to complete. The reason for this is because we could swamp EMOC with a series of actions and may end up with a situation where we are trying to action a Volume attached before the creation of the vServer and Volume have completed.

Exalogic Virtual Tea Break Snippets - What Next After a Exalogic Clean Install

Having installed your Exalogic with the 2.0.1.x software you now have a fairly empty system that simply contains the Control Stack and nothing else. At this point we need to consider what your next steps should be and what we need to define and create before building you Virtual environment. This short blog will provide some recommendations for what you define / build and when based on a number of Exalogic installations. If this sequence is followed then you should have everything in place before your create your first vServer.

The key assumption of this blog entry is that you have spent time designing you virtual landscape and and know what External access etc is required for the resulting system.

Exalogic Virtual Tea Break Snippets - Importing Public Server Template

Before we can create Virtual Servers within Enterprise Manager Ops Centre (EMOC) we will need to import an appropriate Server Template that will be used to create the Virtual Server. Server templates are associated with accounts and hence may be imported on an account by account basis or for common base templates we can import them once and make them Public. Once we have configured the imported template to be Public it will be available to all accounts and users.

Serve templates can be uploaded to an account in 3 simple steps although this initial upload will make the template private to an account its properties can be set to public by simply changing the "Public" flag within the account Server Template tab. The following steps are required to import a template and make it public.

To import a template you will need to navigate to your account and select "Upload Server Template". This will initiate the Wizard below.

Exalogic Virtual Tea Break Snippets - Creating Accounts

Once we have created our Users and Networks we will want to enable the Virtual Data Centre (vDC) for access by the Cloud Users. To facilitate this we will need to create Accounts within the vDC / Cloud and allocate the users to these accounts. Once a Cloud User has been allocated to an account they will be able to access that account and hence create / manage Virtual Servers within that account / Pool.

To create an Account within a vDC / Pool you will need to be logged into Enterprise Manager Ops Centre (EMOC) with the appropriate Role, and this is generally done using you Cloud Administrator, then simply navigate to the vDC Management Accordion, vDC, your Cloud and finally Accounts.

Once you have Accounts highlighted then select "Create Account" via one of the standard methods (Right-Click, Actions or button bar) to initiate the Create Account wizard. If this is the first time you will see an Introduction screen but for subsequent execution this can be disabled. The wizard screens are displayed below.