This chapter is from the book
This chapter is from the book
This chapter is from the book
Getting Everyone On Board with Virtualization
Virtualization introduces many unique and new concepts into your environment, and as a result many groups within IT often put up resistance to it. This is typically a result of the fear and mistrust of a nonstandard technology like VMware and is most often caused by the lack of understanding of how VMware works. Therefore, plan to educate everyone who will be involved in your virtualization project early on so that they have a good understanding about what VMware is and its capabilities and features. Once they learn more about it and discover the great benefits of virtualization, they will be better prepared and more willing to help you implement it. This section provides examples of the types of resistance you will experience from each group and how you can best deal with each of them. You will often find that most people who are initially negative toward VMware eventually become supporters after they learn more about it and experience it for themselves.
The following subsections provide some tips for dealing with specific groups within IT to help them better understand virtualization concepts.
Dealing with Network Administrators
Traditionally, most network groups manage the physical network connection of a server from the switch all the way to the NIC. Virtualization changes that with vSwitches, which effectively extend the physical network from the NIC in an ESX host to a vSwitch that is managed by the ESX server and a virtual NIC that connects a VM to the vSwitch. This vSwitch is usually managed by ESX administrators and not network administrators, which can cause some concern among network administers because they can no longer control and manage part of the network that connects a virtual server to a physical network.
802.1Q VLAN tagging is a network technology commonly used when virtualizing servers. It enables you to use multiple VLANs on a single vSwitch and is a must-have in large environments. Without it, you would have to create a separate vSwitch for each VLAN and dedicate at least one NIC to it. This technology is not used that often with physical servers, and some network people might not have much experience with it. It's fairly simple to set up and configure, and we cover more on this in a later chapter.
Another networking area that is often a concern with virtualization is connecting VMs to your public demilitarized zone (DMZ) while keeping your ESX service console on your private internal network. The concern with this is that the ESX server is straddling the DMZ, because it has connections to both the private and public networks, and a potential attacker could compromise a VM in the DMZ and gain access to your internal network. The design of ESX does not allow for this to occur, and the only scenario in which this could potentially happen is if someone mistakenly configured a VM with two virtual NICs (vNICs), one being on an internal network vSwitch and the other on an external network vSwitch, which you would never want to do (unless the VM is acting as a firewall or proxy server).
Here's what you should tell your network administrators:
- Explain the concept of vSwitches and vNICs and how they interact with physical switches and physical NICs.
- Show them how to set up and configure a vSwitch and how to install a vNIC in a VM and connect it to a vSwitch.
- Explain to them how ESX uses trunked network ports and how 802.1Q VLAN tagging works in a virtual networking environment.
- Explain virtual network security principles and how vSwitches are isolated from each other so that traffic cannot leak between them.
- Demonstrate NIC teaming and failover in a virtual switch.
Dealing with Developers
Many developers will be concerned that their applications may not run properly on virtual servers. Another concern may be that software vendors will not support their products running in virtual environments. Early on in your project, gather support statements from software vendors that show their level of support for virtualization. Demonstrate the snapshot and cloning features of VMware that will be a great benefit to them. Also explain what virtual hardware is and how VMs see the same hardware regardless of the underlying physical hardware (except for the CPU). By having consistent hardware on all servers, you can eliminate any potential problems that may be caused by using different hardware on different servers running the same applications.
Here's what you should tell your developers:
- Show them statements of support for VMware from software vendors.
- Show them a VM's hardware configuration.
- Explain how VM hardware can easily be modified (more RAM, more disk space, and so on).
- Tell them about VMware's capability to rapidly provision new servers and to have dedicated, isolated development sandboxes.
- Show them information about the Lab Manager and Stage Manager automation products that VMware offers as additional components to VI3.
- Demonstrate creating snapshots and reverting back and cloning existing VMs and creating new ones from templates.
Dealing with Security Administrators
This is the group that tends to put up the most resistance to VMware because of the fear that if a VM is compromised it will allow access to the host server and the other VMs on that host. This is commonly known as "escaping the cave," and is more an issue with hosted products such as VMware Workstation and Server and less an issue with ESX, which is a more secure platform.
ESX has a securely designed architecture, and the risk level of this happening is greatly reduced compared to hosted virtual products such as Server and Workstation. This doesn't mean it can't happen, but as long as you keep your host patched and properly secured, the chances of it happening are almost nonexistent. Historically, ESX has a good record when it comes to security and vulnerabilities, and in May 2008, ESX version 3.0.2 and VirtualCenter 2.0.21 received the Common Criteria certification at EAL4+ under the Communications Security Establishment Canada (CSEC) Common Criteria Evaluation and Certification Scheme (CCS). EAL4+ is the highest assurance level that is recognized globally by all signatories under the Common Criteria Recognition Agreement (CCRA).
Another concern when it comes to security is with storage logical unit numbers (LUNs). The concern is that a VM that has its virtual disk on a SAN LUN that is shared with other VMs may allow for an attacker to access other data on that LUN or on the SAN fabric itself. Again, the secure design of ESX specifically prevents this from being possible. A VM cannot directly access the Fibre Channel cards in a host system and therefore cannot see anything beyond the virtual disk assigned to it.
Here's what you should tell your security administrators:
- Show them the industry security certifications that ESX has achieved.
- Explain how the design of ESX does not allow for VMs to directly access host hardware without going through the hypervisor.
- Show them CIS ESX Host and Virtual Machine Benchmarks and Guidelines.
- Allow them access to a VM so that they can verify its security for themselves.
- Show them the vCenter Server roles and very granular permissions that control access to the ESX hosts and VMs.
- Explain the ESX Service Console is not just a Linux operating system but a modified and more secure version based on Red Hat Linux. In addition, explain how ESXi no longer has a Service Console and is less vulnerable than ESX.
- Explain that the guest operating system on a VM is subject to the same security risks as a physical system and if compromised does not allow access to the ESX host.
Dealing with Management
IT management groups are usually the ones that get your funding approved and are typically the ones that sponsor your project. It's important that they understand the technology and its benefits so that they can support you, ensure you get the appropriate funding, and promote your project within the rest of your company.
Here's what you should tell your management:
- Demonstrate some of the cool features that virtualization provides, such as snapshots, VMotion, NIC teaming, and HA.
- Explain the cost-savings benefits and ROI that virtualization can provide (greatly reduced power and cooling costs, for instance).
- Show them the many customer success stories that VMware provides on its website.
- Explain how virtualization can greatly simplify disaster recovery.
- Provide a high-level executive overview of the technology, its features, and how it works.
Dealing with Storage Administrators
Many storage administrators have their own ideas about designing and configuring storage and do not like deviating from them. The most frequent area of contention when deploying ESX is the size of the SAN LUNs. Some old-school storage administrators like creating smaller LUNs (for example, 20GB) and do not like creating the larger LUN sizes that work best with ESX. In addition, assigning storage to ESX servers is a bit different from traditional methods because the same LUNs must all be presented to every ESX server with the same LUN IDs because ESX servers must all see the same storage for features such as VMotion to work.
Here's what you should tell your storage administrators:
- Explain how the VMFS file system is a cluster file system that leverages shared storage to allow multiple instances of ESX Server concurrent read and write access to the same storage resources.
- Explain what a virtual disk file (vmdk) is and how they are used on VMFS volumes.
- Explain how VMFS volumes work best with larger LUNs, and how using extents to enlarge VMFS volumes across multiple LUNs is not a best practice.
- Show them the SAN Configuration guide and the SAN Design and Deployment guide that VMware provides.
- Explain the reduced SAN administration workload that results because there is no need to configure storage for each server (VM) individually; it's only necessary to configure it for each ESX host.
- Explain how ESX servers use multipathing to connect to the SAN fabric.
Dealing with Operating System Administrators
This group will typically be concerned with performance, compatibility, security, and manageability of their servers running in a virtual environment. The biggest concerns are typically resource contention and not knowing how their servers will perform on a virtual host.
Here's what you should tell your operating system administrators:
- Show them how templates work and will allow them to quickly and easily deploy new servers.
- Explain how resource pools work and how resource shares, limits, and reservations can help control the amount of host resources that a VM can access.
- Explain how the VI client and vCenter Server are used to administer ESX hosts and VMs and how roles and permissions are used to assign specific privileges to access both host servers and VMs.
- Explain the key differences between virtual and physical hardware and how the ESX scheduler handles CPU requests.