Creating AWS AMI’s and preparing for the SAP Install

[boobboo]

As we have seen from the earlier posts AWS has a lot of components to be considered and configured in order to use it for SAP.

AMI Instances

It was decided that the quickest route to getting a landscape up and running was to use a Windows based SAP instance. AWS has many public Windows AMI's available for use, from ElasticFox I picked the image - ami-ba517ace, this is a Windows 2003 R2 64Bit release that is on the SAP PAM. Unfortunately there was not an image for Windows 2008 at the time - but they have appeared recently on the AMI lists.

The public AMI needs to be customized in order to be bundled and saved as a private image for use in the POC. To make sure I had a stable AMI to use for all my builds I customised the Public AMI as follows

• Saved a file on the System drive


• Created a new Admin user


• Changed the System name and removed the Sysprep flag

(A more detailed breakdown of the steps can be found here)

Once I had completed these actions I used ElasticFox to bundle the AMI - it is possible to do the same action in the AWS console, but I had issues with the AMI not storing the changed configuration. Which is the last thing you need after spending two days customising the AMI. Bundling can take nearly 30mins

Once the AMI has been customised and bundled, it is necessary to register the AMI.

Before terminating the running instance it is a good idea to launch the new AMI, to test that the bundling process has captured the changes. It is possible to have two or more instances with the same host name running at the same time.

EBS Storage

Although there is a vast amount of storage on the D and E drives, these are wiped upon starting the instances. In order to maintain a persistence of data, disk volumes need to be associated with the Instance.

• Using ElasticFox, create a volume of the required size - the AWS account is only billed for the storage used in the volume

• Enter the size details - be sure to set all volumes in the same Availability zone

• Once the volume is created, it must be attached to the Instance

• In order to have the volume attach to the Instance on the same drive letter every time it is attached to the instance, run the EC2Configservice application

Elastic IP

When the Windows Instance is started, it is given a Public DNS name by AWS. This DNS entry is very unfriendly and set at creation time.

AWS have the ability to assign public IP addresses, ElasticIPs. These can be created and assigned using ElasticFox



Once the IP is allocated it can be assigned to any instance

DNS

Once the ElasticIP is it is possible to create a DNS entry. For the POC I am using DynDNS.org to provide DNS resolution as it is quick and free.

Log into the server and access the DynDNS website, the website will auto-detect the public address



After the ElasticIP is assocated with a DNS entry, enter the DynDNS entry into the hosts file

Once all these infrastructure items are setup the SAP install can be performed as normal.