Books:

Of course I’d love it if you got them my book but there are some other great books out there that they would appreciate also:

• Mastering vSphere by Scott Lowe
• VMware vSphere and Virtual Infrastructure Security: Securing the Virtual Environment by Edward Haletky
• VMware vSphere 4 Administration Instant Reference by Scott Lowe, Jase McCarty and Matthew Johnson
• vSphere 4.0 Quick Start Guide: Shortcuts down the path of Virtualization by Duncan Epping, Alan Renouf, Bernie Baker and Thomas Bryant
• VMware vSphere 4 Implementation by Mike Laverick
• Managing VMware Infrastructure with Windows PowerShell TFM by Hal Rottenberg
• VCP VMware Certified Professional on vSphere 4 Study Guide: Exam VCP-410 by Brian Perry, Chris Huss and Jeantet Fields

Licenses:

VMware admins play with bare-metal virtualization products all day but having a desktop virtualization product like Fusion or Workstation is nice also. Is that big data center in your living room or basement driving you crazy? Using Workstation, admins can run ESX on their desktops and laptops eliminating the need for a data center in your house. Got lots of money to spend? I’m sure they would appreciate an upgrade of their Enterprise licenses to Enterprise Plus or some Cisco Nexus 1000v licenses.

Training:

Every admin wants to learn as much as they can about the products they support. You might consider getting them a classroom training course or if you’re on a budget consider a lower-cost alternative such as this vSphere DVD training course from TrainSignal. This gift could benefit you also, because the smarter your admin is the better the chance that they could find a higher-paying job.

Storage:

You can never have too much storage, flash drives are great but home network storage units are much better. Consider getting them one of the cool new low-cost network storage units from Iomega, Buffalo or Drobo. Or if you want to combine the two than check out this cool gadget that lets you turn flash drives into network storage.

Apparel:

Every VMware admin wants to show off his love for VMware so what better way to do that than with some VMware-branded apparel. From caps to shirts to backpacks to pens you can be sure to find something to please them at the VMware online store.

Gadgets:

Almost every VMware admin is a geek at heart, so what better way to please their inner geek with some cool gadgets. Check out some of these gadgets that are sure to please any admin.

• JuiceBar Portable Solar Charger – You’re already saving lots of power using virtualization, why not save more using a solar charger to harness the power of the sun to charge your mobile devices.
• Flux Capacitor Replica – Want to have the coolest looking datacenter on the planet? Try putting one of these in it to really dress it up, you can tell everyone that virtualization is so great you can run your whole data center with only one of these.
• Cable Monkey Cable Organizer – Messy cables behind servers drive most admins crazy, you can use these cool organizers to straighten up the mess and add some cuteness to your server racks.
• Optimus Maximus Keyboard – If you have more money than you know what to do with, this cool keyboard is sure to make any admin drool. This OLED keyboard is the ultimate computer gadget and the keys can be programmed to display any image and run scripts. Think how cool it would be to have a vMotion key right on your keyboard.

Well that’s just a few suggestions for some great gifts for the VMware admins in your life. If nothing else you might consider expressing your appreciation for their hard work and dedication which is something most administrators often do not hear enough.

Happy holidays too all!

CBT is a new feature in vSphere that can keep track of the blocks of a virtual disk that have changed since a certain point in time. This is extremely useful for backup and replication applications that can use this information to greatly improve incremental backup and replication times. Without CBT these applications have to figure out changed blocks on their own so being able to get this information for free using the vStorage advanced programming interfaces is extremely valuable to them.

CBT is not really part of the vStorage APIs but is a new feature of the VMkernel that is built into the storage stack. The CBT feature can be accessed by third-party applications as part of the vStorage APIs for Data Protection. Applications can use the API to query the VMkernel to return the blocks of data that have changed on a virtual disk since the last backup operation. You can use CBT on any type of virtual disk, thick or thin and on any datastore type except for physical mode Raw Device Mappings. This includes both NFS and iSCSI datastores.

Besides requiring vSphere, a prerequisite for using CBT is that a virtual machine must be using version 7 virtual hardware. While this is the default in vSphere (you can still choose the old version 4 hardware that was used in VMware Infrastructure 3, if you upgraded a host from ESX 3 to ESX 4 you must also upgrade the virtual hardware of the VMs to version 7 to use this feature.

The CBT feature is disabled by default; the reason for this is there is a very small bit of overhead that occurs when using it. However this overhead is a small price to pay for the great efficiencies that happen by enabling it. This feature is not global and can be enabled on only select VMs that you want to take advantage of this functionality. It can be enabled either through the vSphere client or by using the SDK. To enable it in the vSphere client you need to add a configuration parameter to each VM using the below steps:

1. Power off the VM. This is necessary to add a configuration parameter, edit the settings of the VM. Select the Options tab, then under Advanced, General click the Configuration Parameters button.

2. Next, click the Add Row button. You first need to add a general parameter for the VM to enable the feature and then add additional ones for each virtual disk that you wish to enable it on. For the general parameter enter “ctkEnabled” for the name and “true” for the value.

3. For each virtual disk you need to add “scsi#:#.ctkEnabled” for the name where the # signs should be replaced by the controller/disk number for each disk. Usually this is 0:0 for the first disk, then 0:1 for the second disk, etc. Also use “true” for the value for this parameter.

4. Click OK when you are done to save it.

An alternate method to enable CBT is using the SDK. Many backup applications that support CBT will automatically do this for you. For details on using the SDK method see this VMware tech note which describes how to use VirtualMachineConfigSpec and ReconfigVM_Task methods to accomplish this programmatically. Typically you will not want to enable this unless you have a specific application that can utilize this feature such as VMware Data Recovery or Veeam Backup & Replication.

Once enabled a VM must go through what is called a stun/unstun cycle for it to take effect. This cycle happens during certain VM operations including power on/off, suspend/resume, create/delete snapshot. During this cycle a VM’s disk are reopened which allows a change tracking filter to be inserted into the storage stack for that VM. You might wonder where CBT stores the information about changed blocks for a virtual disk, it does this in a special “-ctk.vmdk” file that is created in each VM’s home directory for each virtual disk that it is enabled on.

This size of this file is fixed and does not grow beyond its initial size unless you increase the size of a virtual disk. The size of this file will vary based on the size of a virtual disk which is approximately .5MB for every 10  GB of virtual disk size. Inside this file the state of each block is stored for tracking purposes using sequence numbers that can tell applications if a block has changed or not. One of these files will exist for each virtual disk that CBT is enabled on.

CBT is a great feature that really improves the efficiency and speed of virtual machines’ backup, restore and replication operations in vSphere. Several backup applications have already taken advantage of this new feature and are reporting greatly improved incremental backup times and being able to achieve near continuous data protection because of it.

Special thanks to John Troyer and Jon Bock from VMware and Anton Gostev from Veeam for taking the time to help me better understand the vStorage APIs and CBT.

• I give thanks for High Availability; how many times have you saved the day by bringing my VMs back up on other hosts after a failure?
• I give thanks to the blogging community for providing me with some outstanding information on a daily basis.
• I give thanks to the VMTN communities for getting me started with helping others and showing me how much I enjoy it.
• I give thanks to Distributed Power Management which helps save my company money by lowering our energy bills.
• I give thanks to VMware for inventing the best virtualization product on the market and continuing to make a great product even better.
• I give thanks to John Troyer at VMware who’s always there to help me out if I need anything.
• I give thanks for Storage VMotion which makes my SAN maintenance a piece of cake and limits my VM downtime.
• I give thanks for all the many great friends and acquaintances that I have made in dealing with virtualization, you’re all an inspiration to me.
• I give thanks for being able to live in a time where technology like virtualization is even possible.
• I give thanks for VMotion which makes it so easy to move VMs around between hosts for maintenance purposes.
• I give thanks for Twitter which allows me to communicate daily with all the great virtualization people in the world.

Well that’s plenty to be thankful for. If you have anything virtualization-related to be thankful for also, let us know in the comments.

This release is significant in the fact that is the first update to vSphere which should appease all those who were waiting to upgrade to vSphere for fear of bugs and issues that can be present in the first major release of any software application. There are at least 50 patches that have been issued since vSphere was released that have been rolled into this update, which should lead to increased stability and less headaches for administrators.

This release includes updates to ESX, ESXi, vCenter Server as well as to VMware Data Recovery which has been updated from version 1.0.2 to 1.1. Enhancements to ESX(i) and vCenter Server include the following:

• VMware View 4.0 support - This release adds support for VMware View 4.0, a solution built specifically for delivering desktops as a managed service from the protocol to the platform.

• Windows 7 and Windows 2008 R2 support - This release adds support for 32-bit and 64-bit versions of Windows 7 as well as 64-bit Windows 2008 R2 as guest OS platforms. In addition, the vSphere Client is now supported and can be installed on a Windows 7 platform.

• Enhanced Clustering Support for Microsoft Windows - Microsoft Cluster Server (MSCS) for Windows 2000 and 2003 and Windows Server 2008 Failover Clustering is now supported on a VMware High Availability (HA) and Dynamic Resource Scheduler (DRS) cluster in a limited configuration. HA and DRS functionality can be effectively disabled for individual MSCS virtual machines as opposed to disabling HA and DRS on the entire ESX/ESXi host.

• Enhanced VMware Paravirtualized SCSI Support - Support for boot disk devices attached to a Paravirtualized SCSI ( PVSCSI) adapter has been added for Windows 2003 and 2008 guest operating systems. Floppy disk images are also available containing the driver for use during the Windows installation by selecting F6 to install additional drivers during setup. Floppy images can be found in the /vmimages/floppies/ folder.

• Improved vNetwork Distributed Switch Performance - Several performance and usability issues have been resolved resulting in the following:  Improved performance when making configuration changes to a vNetwork Distributed Switch (vDS) instance when the ESX/ESXi host is under a heavy load. Improved performance when adding or removing an ESX/ESXi host to or from a vDS instance.

• Increase in vCPU per Core Limit - The limit on vCPUs per core has been increased from 20 to 25. This change raises the supported limit only. It does not include any additional performance optimizations. Raising the limit allows users more flexibility to configure systems based on specific workloads and to get the most advantage from increasingly faster processors. The achievable number of vCPUs per core depends on the workload and specifics of the hardware.

• Enablement of Intel Xeon Processor 3400 Series – Support for the Xeon processor 3400 series has been added.

VMware Data Recovery has the following enhancements, most notably better support for file level restores of Windows VMs. Previously in VDR 1.0, file level restore was considered experimental and was done using a command line utility. In VDR 1.1 there is a new Windows file-level restore client to make restores much easier using a GUI interface instead. You can read more about the new FLR capabilities in the VDR 1.1 Administration Guide.

• File Level Restore Functionality is Officially Supported – File Level Restore (FLR) provides a way to access individual files within restore points for Windows virtual machines. In previous versions of Data Recovery, FLR was provided as an experimental feature. File Level Restore feature is now officially supported.

• Integrity Check Stability and Performance Improved – The integrity check process is faster and more stable. Note that integrity checks are computationally intensive processes and can take significant periods of time. The exact amount of time integrity checks take varies based on of the size of the deduplication store. Even with these enhancements, integrity checks that take several hours are not unexpected.

• Integrity Checks Provides Improved Progress Information – When an integrity check is running, a progress indicator is displayed. This progress indicator has been improved, although it does not provide the optimal level of detail.

• Enhanced CIFS Shares Support

As usual read the release notes before upgrading and make sure you follow the standard upgrade order of: vCenter Server>Hosts>Virtual Machines.

ESXi 4.0 Update 1 Release Notes

ESX 4.0 Update 1 Release Notes

vCenter Server Update 1 Release Notes

VMware Data Recovery 1.1 Release Notes

Let’s start with what a vShield Zone is.

A vShield Zone is essentially a virtual security guard for your vSwitches that protects virtual machines (VMs) based on rules you define. If you took a physical firewall and did a physical-to-virtual (P2V) conversion, you would end up with a vShield Zone appliance that is a virtual firewall that works inside an ESX(i) host to protect the VMs on it.

Why would you want a virtual firewall instead of a physical one?

In some cases, a physical firewall can’t protect a VM. For example, if you have multiple VMs on the same vSwitch and port group on a host server, the network traffic between them never leaves the host to travel over the physical network, so a physical firewall cannot provide protection. Virtual firewalls are also complementary to physical firewalls and provide an additional layer of protection for your virtual machines.

What are some uses cases for vShield Zones?

Since a vShield Zone provides a protected area inside a vSwitch you might create one for new VMs until you can properly patch and harden them. Since you can control the port access into and out of the zone you can block all inbound connections and only allow outbound ones on the ports needed to update the server. Once the VM is ready to go out into the often-hostile network world you can move it from the Zone to another vSwitch or port group.

Another use case would be in a demilitarized zone (DMZ) environment; you can configure vShield Zones to sit in front of your VMs so any traffic from the Internet must go through the vShield Zone appliance before it can reach the VMs. With this configuration you can allow only Internet traffic on HTTP ports to reach your VMs to help prevent attacks and exploits that can occur on other TCP/IP ports.

A final use case would be to satisfy some of the many compliance regulations that require segmentation and isolation of certain servers based on their roles to protect them from other VMs and clients. For example the PCI (Payment Card Industry) specification states the following:

Without adequate network segmentation (sometimes called a “flat network”) the entire network is in scope of the PCI DSS assessment. Network segmentation can be achieved through internal network firewalls, routers with strong access control lists or other technology that restricts access to a particular segment of a network.

There is an obvious benefit to implementing segmentation using firewalls to help reduce the scope of your compliance efforts. It can get costly when you try to do this physically; setting up vShield Zone appliances is simple and easy and since it is already included in many editions of vSphere it would not cost you anything.

When I last looked at vShield Zones I felt that it was a decent product that provides an extra needed layer of network security built right into vSphere but lacked some of the robustness that some of the similar third-party vendor products offer. But it does provide all the basic functionality needed to protect your VMs, and since it is already part of vSphere I would recommend checking it out and see if it works for you.

VMware vShield Zones is still a 1.0 product and when I spoke to the team that developed it a while back they seemed very excited and proud of the product so I fully expect future releases of it to get better and better.

For more information on vShield Zones, including what is, how to install and configure it, and tips for using it, see the series of tips I wrote:

Part 1 – VMware vShield Zones: What it is and how it works

Part 2 – Installing and configuring vShield Zones

Part 3 – Quick tips for managing vShield Zones

Improved Storage Resources Control

As the scope of storage resources have increased significantly with large deployments of virtualization environments, so has the need for greater automation and control of these resources. In the vSphere release, vCenter has been enhanced with several new storage specific capabilities to help the virtual administrator manage these environments with a higher degree of control. These enhancements provide administrators with proactive alerts and alarms to address issues before they interrupt the availability of applications running on those resources. vCenter allows setting permissions and quota limits on datastores, as well as per VM.

His question was to explain the meaning of the following line: “vCenter allows setting permissions and quota limits on datastores, as well as per VM.” In particular he wanted to know about setting quota limits on data stores and VMs. While I know a lot about the new permissions in vSphere, particularly for data stores, the part about quota limits confused me also because I have never heard of quota limits in vSphere. I did some research, checked all the vSphere documentation and couldn’t find anything about them. So I contacted VMware to get some clarification and I received the following response from the white paper author:

The quota limit applies to the storage given to a VM.  There is not really an equivalent for a data store.  One can set alarms to notify/alert one when a certain percent-full or overcommit is hit. But I am not aware of a means to stop allocations or placement of VMs when a certain percent overcommit is hit.  That is a common request that I do not believe is there now.

So basically “quota limits” simply  means the amount of disk space assigned to a VM. I guess technically it’s a quota but once you assign the space to the VM you can’t control how much of it that it can use. If you create a 20 GB virtual disk for a VM the guest operating system is going to see all 20 GB of it regardless of whether it is a thick disk or thin disk. If you do overcommit your data stores by using thin disks you need to carefully monitor datastore free space using alarms and reporting. Currently in vSphere there is no way to set any type of quotas for snapshots, virtual disks or datastores.

So while alarms and permissions are greatly improved in vSphere there are really no quota limits that you can use. Perhaps in a future release VMware will put some type of quota controls in place. Thanks to John Troyer and Paul Manning from VMware for the clarification on this.

VMware shifts the paradigm from managing “the raw ingredients of IT”, i.e. component-level infrastructure management, to cloud-based delivery of IT services. This dramatically reduces the cost and complexity of managing IT. VMware vSphere and the VMware vCenter Product Family simplify tedious day-to-day tasks such as provisioning, hardware maintenance, patching and capacity, incident, and performance management through policy-based automation. As a result IT resources and budgets can be shifted from tactical maintenance to strategic projects and innovation that dynamically respond to and ultimately drive the business.

In my experience virtualization has not reduced administrator headcount at all. Why is that? Because the number of servers that we started with before virtualizing was about the same after we virtualized. The only difference being instead of 80 or so physical servers we now only have about six physical servers that were still running those 80 original servers as virtual machines. As a result we may have less physical servers to manage but we now have more operating systems to manage. In addition to the 80 original ones we had six new ones as a result of the ESX hypervisors. So there may be less hardware maintenance which is very minimal to begin with but there are more operating systems to patch and maintain.

One side-effect of virtualizing is VM sprawl. since VMs are so easy to create you tend to quickly end up with a lot more of them after you virtualize. Deploying a new physical server requires money, resources and data center space; deploying a new virtual machine only requires a few mouse clicks. Because of this you usually end up with even more servers to manage after you virtualize then you would have had if you had not virtualized.

When implementing virtualization, existing Windows or Linux system administrators tend to gain the additional duties and title of VMware administrator. When this happens their workloads will usually increase with the additional responsibilities of maintaining the virtual host servers.

So does virtualization really reduce the workload of administrators and allow companies to reduce headcounts? Maybe in some cases when consolidation is incorporated with virtualization projects, or highly-automated tools are put in place to manage the environment. But I’m guessing that there are not many companies that have let people go after virtualizing or have provided existing administrators with lots of extra free time.

Readers, what’s has been your experience, has virtualization reduced your headcount or reduced your server administration? Let us know in the comments.

What is PCoIP?

PCoIP is a relatively new technology developed by a company called Teradici that VMware has chosen to partner with to use this technology in VMware View. Teradici has developed a breakthrough innovation in display compression and propagation over LAN and WAN networks that uses hardware chips on both the host and remote to offload the compression overhead.

PCoIP is a type of display protocol used by remote desktops when doing desktop virtualization, other display protocols including Remote Desktop Protocol, currently used in VMware View and Microsoft Remote Desktop and ICA which is used by Citrix. A display protocol is what delivers the desktop from the host server to the remote user along with capturing mice and keyboard inputs. The current RDP protocol that is used by VMware View has some limitations when using high-resolution desktops and complex graphic situations; VMware has chosen to use PCoIP to improve this. While PCoIP is a new protocol used in VMware View 4 the RDP protocol is still available as an alternative protocol.

While similar to VoIP, PCoIP also delivers HD audio, USB and the user display as well. PCoIP will enable VMware View to deliver the true PC experience that end-users are looking for, which includes high-resolution graphics and rich multimedia, as well as streaming movies and high-definition audio capabilities. For most applications of PCoIP technology the user cannot tell that their PC is not at their desk anymore.

PCoIP implementations today are all hardware-based, meaning you need a graphics card with a Teradici chip in it on your remote host, and a thin-client device with a Teradici card in it to connect from the client end. VMware’s implementation of this in View will be all software based (Soft PCoIP) and will not require any additional hardware on either end. This is similar to the iSCSI storage protocol where you can use either software initiators that are built in to ESX or a separate hardware initiator board. While VMware View uses Soft PCoIP it still supports client hardware devices that have PCoIP built in to them for the best possible performance.

VMware’s software implementation of PCoIP uses Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) over port 50002. The TCP port is used for session establishment and control and the UDP port is used for optimal performance of media and streaming content. All traffic between the host server and remote user is encrypted with 128-bit Advanced Encryption Standard encryption. One of the biggest challenges with remote desktops is dealing with remote users that have low bandwidth and/or high latency network connections; PCoIP handles these types of situations very well and still delivers a decent remote desktop experience to a user.

Like the hardware implementation, the software implementation uses components on both the host and remote user end. The host side is built in to the user desktop that resides on the host server using a View agent and the remote side is built into the View client software.

Because this is done with software instead of hardware that can offload the additional processing needed to compress the display information you might think this will cause additional resource overhead on your host servers, specifically with CPU usage. VMware has done some initial testing and found the impact to the host was negligible and in fact performance was better allowing them to get more desktops on a host server.

This could be because VMware View 4 now runs on vSphere which provides better overall performance than VMware Infrastructure 3 which was used for View 3; VMware is still testing to provide more information on the scalability and performance of PCoIP. You can, however, can use Teradici cards in ESX host servers to offload the extra CPU processing from the host server similar to use hardware initiator cards with the iSCSI storage protocol.

For more information on VMware View 4 and PCoIP visit VMware’s website, and check out the VMware View with PCoIP Information Guide.

In a previous post I covered the basics on what virtualization is and used an analogy to describe it. I also challenged others to submit their own analogies on how they would describe virtualization and received many responses. I thought I would share a few with everyone.

The first is from Rob Bohmann:

Virtualization is like a school bus. Instead of each parent driving their kid to school each day in their car with the resulting traffic jams and waste of time and fuel or having to build lots of extra lanes on the roads, we have the kids ride a big bus that can effectively carry a lot of people. We save resources like gas and space on the highways, as well as the parents’ time.

 

So if you substitute the energy of gas for the energy in electricity, whether derived from coal or nukes or hydro, etc., and the congestion around schools for the space in your data center and the more efficient management and provisioning of servers, I think the analogy works well, especially for people who are not in the technology arena.

The next is from Guy Leech:

The analogy I like to use is that of a block of flats (an apartment building in US speak?) compared with a large house on the same site. It’s the same space but obviously the flats are self contained/isolated and share the utilities. The house has the same utilities but probably doesn’t use anywhere near as much due to the inefficient use of space.

The next is from Michael Nunn:

Imagine you are a parent of four teenage daughters. All your life you have wanted to provide your daughters with their very own “resources,” like their own bedrooms, their own bathrooms, their own computers, their own clothes, etc., but you just could not afford to do it.

What if I could tell you how to give them all everything they wanted and they really believed that they each had their own bedrooms and bathrooms, but in reality you only had to build one bedroom and one bathroom? You would be well within your budget, your daughters would be very happy, and you would not be using space, materials and money to build all those separate rooms.

The next is from Robbie Singh:

Virtualization is similar to utilizing the same resources without even knowing about it. For example, if one person lives in a house he uses the same resources as phone, heat, water, rent, etc. Add one more person and everything remains almost the same. This way both people benefit. It’s like adding two or more servers on the same physical server. Obviously the scale of people vs. resources is the same as physical server to number of virtual servers.

The next is from Kendrick Coleman:

Me: When you go to Subway, you know how they have those six-foot party subs?

Other Guy: Yea

Me: Well think of the 6ft party sub as your typical physical server. Every time you have to deploy a new server, you have to order a six-foot party sub. When you go to subway, do you order a six-foot party sub for lunch?

Other Guy: Well, no.

Me: Why not?

Other Guy: Because you would have a lot of wasted food.

Me: Exactly, so you would probably want five to 10 other people to help you eat that six-foot party sub so nothing goes to waste. With today’s hardware, there are a  lot of wasted resources when you have to deploy a single physical server. Virtualization gives you the ability to have five-10 servers running on that one physical server concurrently so your resources aren’t going to waste. Make sense?

*Editor’s note: Who else thinks Kendrick was eating a Subway sub when he came up with this?  <grin>

The final analogy is elaborate. Mike Laverick often tells it to his students.

In the past, the server was a like a very expensive hotel. It was the worst kind of hotel. It only had one big room and only one person could stay there. However, all employees, whether they were the CEO or copy-boy, had to stay there if they were away on business.

 

This is like the guest operating system being installed to a physical server. Half the time the occupant is out doing other things, asleep, or just lying on the bed surfing up and down the channels looking for the type of channels his wife wouldn’t let him have at home. This is like when Linux or Windows is idling and only using 5% – 10% of CPU or memory. It became considered too costly to build such hotels and filling them with one occupant was very wasteful – because they consume heat, water and power – and most of the time the single occupant either wasn’t there or was asleep!

 

So someone had the idea of a better hotel, one which was divided into a series of different rooms. Each could be different sizes and offer different qualities of service. It didn’t matter what one guest did in one room, as it could not affect others. This hotel had really thick sound insulation so you couldn’t hear the wedding party downstairs or the newlyweds doing newlywed things next door.

On the top floor beyond the bridal suite, were the penthouse suites which were reserved for the high rollers, specifically for Mr. Exchange, Miss, SQL and Mrs. SAP – but in other floors the rooms were barely large enough to swing a small furry animal – this is where Mr. DHCP and Dr. DNS resided. The old hotel was so expensive only people like Howard Hughes could afford a room there – but this new, more efficient, hotel cost the same to build and maintain – and everyone could find a room that was suitable for their needs – from the odd billionaire to the business man on an overnight stay before catching a flight. It also meant we had to build fewer hotels.

 

The other thing we discovered was when Mr. Exchange or Miss SQL weren’t around or sleeping – as they were consuming less resources – their resources could be divvied out to the residents in the hotel to improve their experience. It would be easier to get that table in the fancy restaurant, and it was quicker to get served in the bar. Finally, the old hotel model died a swift and untimely death when the economy fell off the end of a cliff. It became increasingly regarded as a luxury no company could afford. The Hotel Virtualization model ruled the roost because it offered the most flexible model of accommodating guest operating systems with their wildly different resource demands.

Mike provides a very detailed, nice explanation, but I like Kendrick’s the best as it’s simple and easy to remember, and involves food, which is something we all can relate to. So the next time you’re in a position where you have to explain virtualization to a layman, you now have some great analogies you can use.

There are two methods for backing up a VM, traditional backup methods that install an agent inside the OS and back it up file-by-file and image-level backups that back up the single virtual disk VMDK file. Image-level backups are usually done by backup applications that are designed to specifically back up virtual machines, like Veeam Backup and Replication. These applications use the snapshot feature that is built in to VMware to stop disk writes to the virtual disk so it can be safely backed up. Backup applications read the original virtual disk file which is now read-only as new disk writes get written to a newly created delta virtual disk file. Once the backup application has read all the blocks from the original virtual disk file the snapshot is committed, which takes the data from the delta virtual disk and writes it to the original virtual disk. Once this is complete the delta virtual disk is deleted.

In virtual environments it’s more efficient to do image-level backups, but they also offer more options when you need to do a restore. If you want to restore the whole VM to a previous state you can simply restore the whole virtual disk file. Or, if you want to restore individual files, you can easily do this also. When using a backup application for virtual environments the process for individual file restores in virtual machines is easy and straight-forward. For example, Veeam Backup and Replication can quickly mount the backed-up VM disk file from the backup location so it is available for browsing; the files that need to be restored can then be selected and copied back to the original VM, a process that takes only minutes.

VMware’s own VM backup product, VMware Data Recovery can also do individual file restores via a command-line application that mounts the virtual disk from a selected VM/restore point to a Windows drive letter so the files can be accessed and copied. Even if you use simple scripts to back up a VM by copying its disk to another storage location you can restore files easily enough. Virtualization makes this fairly simple as you can just add the backed-up virtual disk file to another helper VM as an additional disk, browse the files on that disk and copy and paste them back to the original VM.

As you can see restoring individual files to virtual machines is a simple and easy process when using a backup application designed to work with virtual machines. It may not be the same process that is used with physical servers and traditional methods, but it is definitely possible and not all that difficult. If anything virtualization makes backup and recovery easier by providing many unique alternative backup and recovery methods then are not possible with traditional methods.