Why is a smaller number of virtual CPUs better?

Note: This article is designed to serve as a high level introduction to the topic and as such uses a very basic explanation. Papers for those that wish to dive into more technical details of the topic are available elsewhere.

In a virtual environment such as VMware or Hyper-V, multiple virtual machines (VMs) operate on the same physical hardware. In order to make this function, a small piece of software, called a hypervisor operates to schedule the virtual resources with the physical hardware. As a virtual machine enters a state where CPU resources are required the VM is placed into a CPU ready state until enough physical CPUs are available to match the number of virtual CPUs.

The hypervisor will schedule VMs to available physical resources until all resources that can be scheduled are used.

Each VM will run on the physical CPUs until either it needs to wait for an I/O operation or the VM uses up its time slice. At that point the VM will either be placed into the I/O wait state until the I/O completes or be placed back in the ready queue, waiting for available physical resources.

As physical resources become available, they hypervisor will schedule VMs to run on those resources. In some cases, not all physical resources will be in use, due to the number of virtual CPUs required by the VMs in the ready state.

The process continues as VMs either wait for I/O or use their time slice on the physical CPUs.

In some cases there are no VMs in the ready state, at which point the scheduled VM will not time out until another VM requires the resources

Often a VM with fewer virtual CPUs will be able to be scheduled before one with more virtual CPUs due to resource availability.

In some cases a VM will complete an I/O operation and immediately be scheduled on available physical resources.

Algorithms are in place to ensure that no VM completely starves for CPU resources but the VMs with more virtual CPUs will be scheduled less frequently and will also impact the amount of time the smaller VMs can utilize the physical resources.

A VM with high CPU utilization and little I/O will move between the ready queue and running on the CPUs more frequently. In this case, the operating system will report high CPU utilization, even though the VM may not be running for a majority of the real time involved.

In these situations, operating system tools that run within the VM may indicate that more CPUs are required when, in reality, the opposite is actually the case. A combination of metrics at the hypervisor and at the operating system level is usually required to truly understand the underlying issues.

Lewan Named to 2015 Tech Elite 150 List

For the third year in a row, Lewan has been recognized for our exemplary approach to delivery of Managed IT Services and been awarded a spot on the 2015 MSP Elite 150 list, part of CRN’s Managed Service Provider 500 (MSP500) list. The Elite 150 group is recognized as large data center-focused solution providers with a strong mix of on-premise professional services as well as off-premise services.

From CRN:

This annual list distinguishes the top technology providers and consultants in North America whose leading approach to managed services enables their customers to improve operational efficiencies, elicit greater value from their IT investments, and successfully leverage technology to achieve greater competitive advantage.

In today’s world of outsourced IT, the expertise of MSPs has become increasingly important to organizations. The plethora of choices in terms of consumption and procurement of technology can become overwhelming. To help facilitate companies’ selection and adoption of managed services and providers, CRN, the leading media outlet for technology vendors and solution providers who serve end-user customers, has identified the top 500 MSPs.

“The allure of Everything-as-a-Service to organizations is largely rooted in the appeal of predictable operational expenses, cost-cutting, resource allocation and access to on-demand/pay-as-you-go technology. Therein lies a great need for the expertise of managed service providers,” said Robert Faletra, CEO, The Channel Company. “We congratulate the managed service providers who have engineered, or re-engineered, their businesses to deliver the services their customers rely on for future growth and ongoing success.”

Lewan Named to 2014 Tech Elite 250 List

Lewan has once again earned a prestigious spot on CRN’s 2014 list of Tech Elite 250 IT Solution Providers. This elite group of IT solution providers have invested in the training and education needed to earn the most advanced technical certifications from leading vendors.

Lewan Technology, CRN Tech Elite 250From CRN:

In compiling the list, CRN editors worked with The Channel Company’s research group to define the most customer-beneficial technical certifications in the IT channel. These technical certifications – from vendors including Cisco, Citrix, Dell, HP, NetApp, Microsoft, VMware, and Symantec – have enabled solution providers to deliver the most premium products, service and support to their North American customers.

“The solution providers highlighted on our annual Tech Elite 250 have demonstrated a commitment to excellence and gained industry credibility by investing in the IT certifications necessary to stay competitive and deliver the highest level of service to their customers,” said Robert Faletra, CEO, The Channel Company. “These featured solution providers have enhanced and strengthened their partnerships by earning some of the most difficult certifications from some of the biggest names in IT. We congratulate these organizations and look forward to their continued success.”

Thinking about a VDI initiative? Watch this.

Lewan Solutions Architect, Kenneth Fingerlos, wowed the crowd last month at the GPU Technology Conference (GTC) 2014 with his presentation on VDI, “Virtual is Better than Physical Delivering a Delightful User Experience from a Virtual Desktop“.

GTC is the world’s biggest and most important GPU developer conference. Taking place in Silicon Valley, GTC offers unmatched opportunities to learn how to harness the latest GPU technology, along with face-to-face interaction with industry luminaries and NVIDIA experts.

Leveraging his industry leading expertise, Kenneth “delivered in spades,” as described in a review of his presentation for The Register:

The VDI talk was the kind of GTC session I love. It’s where a real-world expert talks about how a difficult task is actually accomplished. Not the theory, not how it should work on paper, but what it takes to actually move a project from Point “A” to Point “We’re done with this”.
Ken Fingerlos from Lewan Technology delivered in spades with his “Virtual is Better than Physical: Delivering a Delightful User Experience from a Virtual Desktop” GTC14 session. Delightful? Hmm…In my past lives, I’ve had to use some virtual PCs and my experience ranged from “absolutely unusable” to “omg I hate this”.
It’s easy to see that Fingerlos has been around the block when it comes to VDI. He has all the right credentials, ranging from VMware to Citrix to Microsoft. But more importantly, he’s been there and done it.

Read the complete review from theregister.co.uk

Kenneth’s GTC Presenter’s Bio

View the complete session and slide deck:
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Creating a Recurring Email in Windows Server 2008 Using Exchange 2010

On occasion, an organization may have a need to send a recurring email. In the case of one of our customers, there was a need to send a weekly notice to users that patches would be applied to the terminal servers overnight with a friendly reminder to save any work. To set this up is really quite simple. Here is how:

First, open the Task Schedule and choose Create Task. This will open the Task Properties window.

Task Scheduler ActionsOn the General tab of the Task Properties window, fill in a Description. Choose the user account from which you would like to send the email. Finally, choose “Run whether user is logged on or not” and “Run with highest privileges.

Task Scheduler Task PropertiesOn the Triggers tab, click New. Make selections as appropriate for the frequency and be sure to check Enabled.

On the Actions tab, choose “Send an e-mail” from the Action drop-down menu. Fill out the From, Subject, and Text of the message. Add any appropriate attachment and fill in the SMTP server address. If the Scheduled Task is being configured on your Exchange server, you can simply enter 127.0.0.1 for the SMTP server. Click OK to return to the Task Properties window.

Task Scheduler New ActionOn the Conditions tab, specify the conditions under which the task should run.

On the Settings tab, you should choose  “Allow task to be run on demand”.

After clicking OK to close all the Windows, right-click the task, and click Run to test. Ensure that the test email is received by the intended recipient(s).

In some instances, you may need to configure a Receive Connector on your Exchange server which allows anonymous relay. You can find a instructions for doing that on Microsoft’s website here.

How to uninstall newer versions of Internet Explorer

Some web applications are picky about the browser you need to use.  Websites and web-based applications will usually tell you what they are designed for and what you should access them with.  Niche applications tend to be especially picky as smaller development teams can’t optimize complex web-based apps for the gamut of browsers available.

One of the most common issues seems to be Internet Explorer being upgraded through Windows Update causing compatibility problems.  Luckily it’s fairly simple to “downgrade” to a version that works best with what you need to access.  The installation is a little bit tougher to find than most installed programs, but not by much.

First off, go to the Control Panel on your system.  This can be found by clicking the “Start” button, then selecting Control Panel from the Start menu.  From the Control Panel, select “Uninstall a program” if the view is set to Category (default for Windows 7), or select “Programs and Features” from either the Small Icons or Large Icons view.

Now select “View installed updates”
controlpaneloptions

Sort the list by Name by left-clicking on the “Name” tab.
sortbyname

Scroll all the way to the bottom of the list.  The Internet Explorer update will always be at the bottom of the list when sorted by Name.uninstall IE10

Select Windows Internet Explorer 10 (or Windows Internet Explorer 9 if going from 9 to 8) and then click on Uninstall.  Your system will need to be restarted, but this will revert you to the previous version if you need to do so for compatibility with websites or web-based applications.

If your print job is “stuck” and you can’t cancel or delete it, try this: manually clearing the print spooler. (Windows)

A little background: when you send the command to print a file, Windows “spools” those files – it creates a temporary copy for the printer’s use.  This allows the printer to access the file at its own rate, and continues the job even if you (hypothetically) close the program or file you have open.  Sometimes, for various reasons that aren’t particularly relevant to this article, printers will fail to successfully complete a job.  Usually, you can just cancel the job or delete it from the printer’s queue – the easiest way to access this is to double-click the icon that looks like a printer in the rightmost area of the Windows taskbar.

print icon

The following window will appear showing your print job(s) and their status.  You can right click on these and pause, restart, cancel, and basically manage the individual entries.

printqueue

When a failed print job cannot be removed this way, or if the job just seems stuck, we can force Windows to remove it and restart the “service” that Windows uses to send data to printers.

To do this, click on the “Start” button, and just begin typing the letters CMD.  Windows will find and present a program called “cmd.exe.”  Right click on this item (the icon is a black window with white letters saying “C:\”) and select “Run as Administrator.”

Copy and paste or type the following commands in this order
(to paste in this command line window, right click on the title bar -> Edit -> Paste)
rightclickoncmdtitlebar

The commands – be sure to include everything within the quotations:

  1. “net stop spooler”
  2. “del /F /Q C:\Windows\System32\spool\PRINTERS\*”
  3. “net start spooler”

You will see feedback after stopping and starting the spooler, but the second command simply removes all of the temporary “spooled” files in the Windows print system.  CMD.exe will not give you any indication that it performed a task after this line, but it will clear all spooled items.

Lastly, try printing your document again.  It will very likely print successfully.