At the time, I read their entries and thought it was a really cool project, allowing for more free access in the virtualization arena. I knew that this would have value moving forward, but initially did not grasp the implications of introducing this new technology.However, as I was discussing backup strategies between Dell|EqualLogic storage and VMware, I discovered where this could have significant impact.

When we host VMFS iSCSI volumes on the EQL SAN, we can leverage the Auto Snapshot Manager for VMware to create application-aware snapshots of quiesced Virtual Machines. To date, these storage snapshots have only been for DR or volume-level recovery purposes. We still needed to rely on VCB or third party applications to backup the Virtual Machine files.

With the evolution of this VMFS driver, we will now be able to use that ASM quiesced snapshot to streamline Virtual Machine backups. First, we mount the snapshot to our backup server. Using the open source VMFS driver, we will now be able to browse that snapshot volume and see all of the files within. Backups of this volume can happen directly, without the need to use an intermediary such as VCB or a third party application. Direct backups are faster and less complex, and therefore… easier to manage. And as all SysAdmins know, easier to manage is always better

VMware View3 – the new name for VDI – can give cost savings on several fronts. Simply by switching from standalone PCs on the desktop to a thin client and VMware View3 you can save around 45% on hardware and power costs. When you factor in the decreased management overhead from standardizing the infrastructure on a single base image and application virtualization and deployment with the ThinApp features, it increases the margin by decreasing problem calls to the HelpDesk.

However, this sort of infrastructure rollout isn’t for everyone. VMware is suggesting a target audience of companies that have over 200 managed desktops. Less than that, and the cost and management savings aren’t as dramatic.

Central management of the desktop image, ThinApp deployment, linked clones through the View Composer feature to decrease backend storage requirements, and the offline desktop client allow for a large range of features to manage the enterprise desktop. This is even more dramatic if the customer has an existing VMware installation, as there will be minimal training overhead to roll out the solution within their own infrastructure design.

Check out this Desktop Virtualization white paper — decent overview from a VMware perspective.

To begin with, think of yourself around the holidays with a list of presents to buy at the Mall. If you have ten purchases from ten different stores to make this afternoon, it may take you a couple of hours to get through the entire list. However, if you had to bring five kids with you to the mall for the day, it would take you significantly longer to get through the same shopping list. The overhead of managing the childrens’ needs during the trip adds a good deal of overhead to your workload that impacts the amount of time you dedicate to present acquisition.

This scenario plays itself out when comparing Xen and Hyper-V to VMware’s ESX. VMware’s ESX is a ‘bare metal’ installation. This means that the hypervisor is installed directly onto the server. At only 32 MB in size, ESX is optimized to manage the Virtual Machine I/O and hardware translation with very little overhead. It also allows ESX to over allocate resources such as memory leveraging direct control over the physical resources.

With XenServer and Hyper-V, both installations use a base or core OS. This installed Operating System manages the hardware similar to what happens in any other server installation. The hypervisor is then installed and is run in the core OS. It is this hypervisor that manages the interaction between the hosted VMs and the hardware. The significant difference is that the core OS manages the hypervisor rather than having the hypervisor installed directly onto the hardware itself. With the OS management as a filter/management interface between the hypervisor and hardware, it offers a layer of complexity that is absent in the VMware ESX offering.

Similar to bringing along several kids with you to the mall, a hosted hypervisor will always have additional overhead associated with the core OS that you won’t have with VMware’s ESX. Additionally, because ESX controls the hardware directly, there is significant savings that can be realized in resource over allocation that can’t be found in hosted hypervisors. Hosted hypervisors can only allocate a subset of their physical resources to VMs, where ESX can optimize and prioritize the resources to get the most out of the physical assets.

So next time you are wondering about the difference between hypervisors, think of your last trip to the mall and smile.

Citrix XenServer offers virtualization based on the open source Xen engine. This is the same release that was previously sold as the enterprise product. Included in the package is their multi-node management interface, live motion of VMs from one node to another, and integrated storage management to support host based logical volume management. These features are more versatile and diverse than VMware’s free offering, ESXi, giving them an edge in the free hypervisor marketplace. While comparison to ESXi grants Citrix XenServer the edge with features such as Live Motion that aren’t offered by VMware without VCenter and licensing.

This puts VMware on notice that they will have significant competition in the SMB space. XenServer has more features than the free ESXi offering, but not as mature of feature rich as VMware’s VI3 Virtual Infrastructure. I don’t see enterprise customers looking to Citrix, but at the price point, it may open a few doors in the smaller marketplace.

Microsoft Hyper-V and VMware ESX are hypervisor based solutions. They install directly on the hardware and require no lower level OS beneath them, however their architecture is quite different.

The hypervisor is a critical component of and foundation of virtual infrastructures. Fundamental characteristics of a hypervisor are:

• Have a purpose-built, thin OS independent architecture for enhanced reliability and robustness
• Make optimal use of available hardware resources
• Deliver performance acceleration features that support mission critical applications
• Enable advanced capabilities not previously possible on physical systems

ESX installs a hypervisor on the hardware. It acts as the intermediary between the hardware and any virtual machines running on the server. Hardware device drivers are included in the hypervisor. This is called a direct driver model.

Hyper-V also installs on bare metal. But all management functions and access to hardware is controlled via a “root partition” that runs the Windows Server (or Server Core) 2008 OS. This root partition is actually a special virtual machine, through which hardware I/O requests from child partitions travel via the VMBus architecture. This is called an indirect driver model. So basically before you enable the Hyper-V role, your server OS is of the typical architecture, after enabling the role, Hyper-V installs itself on top of the hardware, and places your original OS into this special virtual machine, the root partition.

A comparison of certain key features between platforms:

• ESX supports both 32 & 64-bit hosts, Hyper-V requires a 64-bit host that supports hardware-assisted virtualization. All platforms support 32 or 64-bit guests.
• Maximum Logical Host CPU’s: ESX = 32, Hyper-V = 16 (can do more, but not supported)
• Maximum Supported Host Memory: ESX = 256 GB, Hyper-V = 2 TB (2008 Enterprise Ed.)
• Maximum Memory per Guest OS (VM): ESX & Hyper-V = 64 GB
• Maximum Supported Running VM’s: ESX = 128, Hyper-V = limited only by available resources
• RAM Over-Commitment: Supported in ESX, not supported in Hyper-V. (This allows RAM allocated to VM’s to exceed actual available RAM in host).
• NIC Teaming: Native support in ESX. Hyper-V only supports via 3rd party drivers.
• Maximum # Virtual Switches: ESX = 248, Hyper-V = unlimited

VMotion lets you:

• Automatically optimize and allocate entire pools of resources for maximum hardware utilization and availability.
• Perform hardware maintenance without any scheduled downtime.
• Proactively migrate virtual machines away from failing or underperforming servers.

So how Does VMotion work?

First, the entire state of a virtual machine is encapsulated by a set of files stored on shared storage. VMware’s clustered Virtual Machine FileSystem (VMFS) allows multiple installations of ESX Server to access the same virtual machine files concurrently.

Second, the active memory and precise execution state of the virtual machine is rapidly transferred over a high speed network. This allows the virtual machine to instantaneously switch from running on the source ESX Server to the destination ESX Server. VMotion keeps the transfer period imperceptible to users by keeping track of on-going memory transactions in a bitmap. Once the entire memory and system state has been copied over to the target ESX Server, VMotion suspends the source virtual machine, copies the bitmap to the target ESX Server, and resumes the virtual machine on the target ESX Server. This entire process takes less than two seconds on a Gigabit Ethernet network.

Third, the networks used by the virtual machine are also virtualized by the underlying ESX Server. This ensures that even after the migration, the virtual machine network identity and network connections are preserved. VMotion manages the virtual MAC address as part of the process. Once the destination machine is activated, VMotion pings the network router to ensure that it is aware of the new physical location of the virtual MAC address. Since the migration of a virtual machine with VMotion preserves the precise execution state, the network identity, and the active network connections, the result is zero downtime and no disruption to users.

VMware Infrastructure addresses security in a number of ways. Some of these include:

• Compatibility with SAN security practices. VMware Infrastructure enforces security policies with LUN zoning and LUN masking.
• Implementation of secure networking features. VLAN tagging enhances network security by tagging and filtering network traffic on VLANs, and Layer network security policies enforce security for virtual machines at the Ethernet layer in a way that is not available with physical servers.
• Integration with Microsoft® Active Directory. VMware Infrastructure allows you to base access controls on existing Microsoft Active Directory authentication mechanisms.
• Custom roles and permissions. VMware Infrastructure enhances security and flexibility with user-defined roles. You can restrict access to the entire inventory of virtual machines, resource pools and servers by assigning users to these custom roles.
• Resource pool access control and delegation. VMware Infrastructure secures resource allocation at different levels in the company. For example, when a top-level administrator makes a resource pool available to a department-level user, all virtual machine creation and management can be performed by the department administrator within the boundaries assigned to the resource pool.
• Audit trails. VMware Infrastructure maintains a record of configuration changes and the administrator who initiated each one. You can export reports for event tracking.
• Session management. VMware Infrastructure lets you discover—and if necessary—terminate VirtualCenter user sessions.

A more powerful server and lower application resource demand means you can host a greater number of virtual machines. Conversely, lower box power and higher application resource demand mean fewer virtual machines per physical server.

That’s why at Mosaic as a first step in any virtualization we give our customers an informal VM Capacity Discovery session. We can give a first level assessment of what level of consolidation to expect.

So why is this a great time for virtualization projects? Simply because the ROI on virtualizing your datacenter can be less than a year, saving you money on your bottom line THIS budget year! Depending on the size of your datacenter, and your new server refresh cycle, you may be able to repurpose this year’s budget to a virtualization project and actually decrease your bottom line.

I know, that sounds almost impossible, but let me show you how it works. Assuming that you have a datacenter that is populated with … say 50 servers. They can be a mix of Windows, Linux, or other x86-based hosts. Another assumption is that of the 50 servers, you are retaining them 4 years, and replacing them on a regular cycle, at probably 12 new servers per year. After memory, drives, etc, you are looking at probably $5,000 each for a ballpark number of $60k per year for new server purchases.

If you were to virtualize your datacenter with VMware, you should be able to migrate 40 of your existing servers to VMs as part of the project. In an ideal world, we could virtualize them all. However there may be a few servers that require unsupported expansion cards, are being outsourced, or are true ‘high performers’ that are not suitable virtualization candidates. A conservative estimate would be that we could support 40 virtual machines within a 3 host ESX infrastructure. It would be very feasible to re-purpose an existing server as your Virtual Center management server. Therefore, rather than purchase 12 new servers for this year, you would only require 3 new servers.

VMware’s VI3 infrastructure requires shared network storage to fully utilize the feature set. Assuming that you don’t have a SAN in your datacenter, you would need to purchase one for this solution. You can purchase a 4TB Dell EqualLogic iSCSI SAN for less than $25,000. Also, the VMware software itself can be purchased as a bundle for around $20,000 as well for 3 ESX hosts and Virtual Center. Now you have all of the pieces you need to virtualize your datacenter.

OK, strap in tight because here comes the math that you are all waiting to see.

So you are asking yourself “You said I could SAVE money, not break even. I don’t see any difference between this project and what I am already spending.” Here are a few points that allow you to save money that aren’t shown above.

1) You will now be supporting 14 servers and an iSCSI SAN in your datacenter instead of 50 servers. There is a significant drop in Power, cooling, rack space, KVM and network ports required in your datacenter now. You will see direct savings on your datacenter operational budget over the course of the year, somewhere in the area of 10%-30% reduction in utility bills. There may also be ‘green initiatives’ in your state that will pay you rebates for reducing your electrical footprint in the datacenter.

2) Server maintenance and upkeep costs will drop. As you no longer need to support your physical servers after they come off warranty, you will save on hardware maintenance both this year and in future budget cycles.

3) Server and Service downtime. Once your datacenter is virtualized, you will see a dramatic increase in server uptime and performance based on VMware’s HA and DRS clustering features. By optimizing VM performance and load across the cluster, you will see better uptime by proactively migrating hosts to available hosts in the event of both planned and unplanned downtime for your ESX hosts.

4) Administrative costs reduced. By virtualizing your datacenter, you significantly reduce the need for overtime or on-call expenses. Virtual Servers and host management can be done remotely, reducing administrative overhead. Additionally, as you decrease hardware dependencies, you reduce the number of outages due to failed memory, hard drives, network cards, etc.

5) Backup, recovery, and Disaster Recovery costs reduced. By virtualizing with VMware and EqualLogic, you are able to use your existing backup server infrastructure to backup the VMs. However, you will save costs on the number of backup agents that you need. Using EqualLogic’s Snapshot Manager for VMware feature, you can perform snapshots of all of your virtual machines from the SAN snapshot directly from your backup server. This reduces the number of agents from 40 to only 1 on the backup server. Additionally, since VM backups are simply 2-3 files, it is easy to recover an entire VM in event of a disaster. Since ESX can be installed on most industry standard hardware, a VM configured for a Dell server can run on a HP host in a DR location.

In conclusion, if you look at simply the cost layout of virtualizing as opposed to continuing down the rack-mounted individual server route in your datacenter, there is comparable costs involved. However, if you factor in the ancillary costs of doing business in the datacenter, you will see direct savings to your bottom line as soon as you make the switch to a VI3 Virtual Datacenter. Costs such as utilities, network support, server maintenance, administrative resources, downtime, backup agents, and DR projections can be significantly reduced in the Virtual Datacenter. While these are not directly associated with a virtualization project, they are realized within the datacenter as a whole. These cost reductions are also not a one-time reduction to the bottom line. They persist across budget cycles and ongoing savings to the overall datacenter operation for years to come.