In many projects my colleagues often ask me what VM templates I must create, and how many resources I must assign to it.
The first thing should to do is identify the workload or the business logic that platform must sustain during its lifetime. In the case of a service provider, templates, follow the simple list of products; but in the case of a dedicated project or private cloud consolidation, the analysis of the workload is mandatory to identify which and how many templates must be created:
|VM1||Windows 2008||Prod1||2vCPU, 8GB RAM, 150 GB vmdk|
|VM2||Windows 2012||Prod1||2vCPU, 8GB RAM, 50 GB vmdk|
|VM3||Windows 2012||Prod1||1vCPU, 4GB RAM, 50 GB vmdk|
|VM4||Windows 2012||Prod2||1vCPU, 4GB RAM, 50 GB vmdk|
|VM5||Windows 2012||Prod2||1vCPU, 4GB RAM, 50 GB vmdk|
|VM6||Windows 2012||Prod2||4vCPU, 16GB RAM, 200 GB vmdk|
|VM7||Windows 2012||Prod1||2vCPU, 8GB RAM, 50GB vmdk|
First of all, identify the Operative Systems:
- Windows 2008
- Windows 2012
In this Windows 2008 could be excluded from the templating project because is the one in the project, and assume that the future instances should be Windows 2012 only. Then VM template list could be:
The next consideration is the network and/or the environment, because time to deploy of a VM could be decreased in a environment with dhcp and active directory: during deploy you could automatically join active directory, without next manual intervention. <<Less manual intervention for better life of the sysadmin>>.
Last but not the least is identifying the minimum resources the template should have. for vCPU and Memory you could follow the minimum requirements for the OS or identify the minimum parameter in the list. In our case 1 vCPU and 4GB vRAM. But for vmdk the rule could be different: you could extend your disk increasing vmdk capacity or binding another vmdk, but reducing could be dangerous, complex and insecure. For this reason, it must consider the minimum capacity for OS or the minimum parameter in the list.
Template list could be this:
|TPL1||Windows 2012||Prod1||1vCPU, 4GB RAM, 50GB vmdk|
|TPL2||Windows 2012||Prod2||1vCPU, 4GB RAM, 50GB vmdk|
Enjoy your deploy.