Monthly Archive: October 2012

Oct 22 2012

Veeam’s giving away cool stuff – don’t miss out

veeam-giveaway

Veeam is doing a give away every month until August 2013 where you have the chance to win some cool things like iPads, Microsoft Surface tablets and VMworld 2013 passes. I’m a tablet junkie and the new Surface tablet looks pretty cool, I’ll be definitely adding one to my tablet collection at some point. Unlike some of the Android tablets that are pushing the price point down to under $200, the Surface will be priced at $499 without the smart keyboard for the base model with 32GB of RAM and $599 with the smart keyboard. They’re not cheap so being able to win one for free will save you a lot of cash.

So how do you win, it’s easy, go to this link and put in your name and email address, if you’re one of the lucky ones Veeam may pull your name and a new tablet may be on the way to you. You can’t win unless you sign-up, it’s easy and painless so what are you waiting for.

Want to be a guaranteed winner, also check out Veeam’s Backup Academy which provides free training on data protection technology. I was one of the course instructors along with David Davis, Greg Shields and Rick Vanover. This is a great way to improve your knowledge on backup & recovery with 15 modules focused on specific topics and it won’t cost you a cent. So head on over there and get smarter.

Oct 17 2012

Understanding CPU & Memory Management in vSphere

cpumemory

CPU & memory resources are two resources that are not fully understood in vSphere, and they are two resources that are often wasted, as well. In this post we’ll take a look at CPU & memory resources in vSphere to help you better understand them and provide some tips for properly managing them.

Let’s first take a look at the CPU resource. Virtual machines can be assigned up to 64 virtual CPUs in vSphere 5.1. The amount you can assign to a VM, of course, depends on the total amount a host has available. This number is determined by the number of physical CPUs (sockets), the number of cores that a physical CPU has, and whether hyper-threading technology is supported on the CPU. For example, my ML110G6 server has a single physical CPU that is quad-core, but it also has hyper-threading technology. So, the total CPUs seen by vSphere is 8 (1 x 4 x 2). Unlike memory, where you can assign more virtual RAM to a VM then you have physically in a host, you can’t do this type of over-provisioning with CPU resources.

Most VMs will be fine with one vCPU. Start with one, in most cases, and add more, if needed. The applications and workloads running inside the VM will dictate whether you need additional vCPUs or not. The exception here is if you have an application (i.e. Exchange, transactional database, etc.) that you know will have a heavy workload and need more than one vCPU. One word of advice, though, on changing from a single CPU to multiple CPU’s with Microsoft Windows: previous versions of Windows had separate kernel HAL’s that were used depending on whether the server had a single CPU or multiple CPUs (vSMP). These kernels were optimized for each configuration to improve performance.  So, if you made a change in the hardware once Windows was already installed, you had to change the kernel type inside of Windows, which was a pain in the butt. Microsoft did away with that requirement some time ago with the Windows Server 2008 release, and now there is only one kernel regardless of the number of CPUs that are assigned to a server. You can read more about this change here. So, if you are running an older Windows OS, like Server 2000 or 2003, you still need to change the kernel type if you go from single to multiple CPUs or vice versa.

So, why not just give VMs lots of CPUs, and let them use what they need? CPU usage is not like memory usage, which often utilizes all the memory assigned to it for things like pre-fetching. The real problem with assigning too many vCPUs to a VM is scheduling.  Unlike memory, which is directly allocated to VMs and is not shared (except for TPS), CPU resources are shared and must wait in a line to be scheduled  and processed by the hypervisor which finds a free physical CPU/core to handle each request. Handling VMs with a single vCPU is pretty easy: just find a single open CPU/core and hand it over to the VM. With multiple vCPU’s it becomes more difficult, as you have to find several available CPUs/cores to handle requests. This is called co-scheduling, and throughout the years, VMware has changed how they handle co-scheduling to make it a bit more flexible and relaxed. You can read more about how vSphere handles co-scheduling in this VMware white paper.

When it comes to memory, assigning too much is not a good thing and there are several reasons for that. The first reason is that the OS and applications tend to use all available memory for things like caching that consume extra available memory. All this extra memory usage takes away physical host memory from other VMs. It also makes the hypervisors job of managing memory conservation, via features like TPS and ballooning, more difficult.  Another thing that happens with memory is when you assign memory to a VM and power it on; you are also consuming additional disk space. The hypervisor creates a virtual swap (vswp) file in the home directory of the VM equal in size to the amount of memory assigned to a VM (minus any memory reservations). The reason this happens is to support vSphere’s ability to over-commit memory to VMs and assign them more than a host is physically capable of supporting. Once a host ‘s physical memory is exhausted, it starts uses the vswp files to make up for this resource shortage, which slows down performance and puts more stress on the storage array.

So, if you assign 8GB of memory to a VM, once it is powered on, an 8GB vswp file will be created.  If you have 100 VMs with 8GB of memory each, that’s 800GB of disk space that you lose from your vSphere datastores. This can chew up a lot of disk space, so limiting the amount of memory that you assign to VMs will also limit the size of the vswp files that get created.

Therefore, the secret to a healthy vSphere environment is to “right-size” VMs.  This means only assigning them the resources they need to support their workloads, and not wasting resources. Virtual environments share resources, so you can’t use mindsets from physical environments where having too much memory or CPUs is no big deal. How do you know what is the right size is? In most cases you won’t know, but you can get a fairly good idea of a VM’s resource requirements by combining the typical amount that the guest OS needs with the resource requirements for the applications that you are running on it. You should start by estimating the amount.  Then the key is to monitor performance to determine what resources a VM is using and what resources it is not using. vCenter Server isn’t really helpful for this as it doesn’t really do reporting. So, using 3rd party tools can make this much easier. I’ve always been impressed by the dashboards that SolarWinds has in their VMware monitoring tool, Virtualization Manager. These dashboards can show you, at a glance, which VMs are under-sized and which are over-sized. Their VM Sprawl dashboard can make it really easy to right-size all the VMs in your environment so you can reallocate resources from VMs that don’t need them to VMs that do.

solarwinds1

Another benefit that Virtualization Manager provides is that you can spot idle and zombie VMs that also suck away resources from your environment and need to be dealt with.

So, effectively managing your CPU and memory resources is really a two-step process. First, don’t go overboard with resources when creating new VMs. Try and be a bit conservative to start out.  Then, monitor your environment continually with a product like SolarWinds Virtualization Manager so you can see the actual VM resource needs. The beauty of virtualization is that it makes it really easy to add or remove resources from a virtual machine. If you want to experience the maximum benefit that virtualization provides and get the most cost savings from it, right-sizing is the key to achieving that.

Oct 10 2012

Storage vMotion Links

vSphere 5.1 Storage Enhancements – Part 7: Storage vMotion (CormacHogan.com)
vSphere 5.1 storage vMotion parallel disk migrations
(Frank Denneman)
Video: vSphere4 Unleashed: 06 – Storage vMotion
(Hypervisor)
The Design and Evolution of Live Storage Migration in VMware ESX
(VMware Technical Paper)
Under the Covers with Storage vMotion (VMware Uptime Blog)
Enhanced Storage vMotion and vSphere (YouTube)

Oct 06 2012

Top 10 things you must read about vSphere 5.1

There has been so many documents, white papers, videos and blog posts posted about the vSphere 5.1 release that it’s hard to keep up with them all. I have at least 250 links gathered in my vSphere 5.1 Link-o-rama and it is still growing. With so many links it’s easy to miss some of the really good ones so I thought I would put together a top 10 list that highlights the ones that you don’t want to miss.

top10list-crop

1 – VMware’s What’s new in vSphere 5.1 white paper series

VMware released a series of technical white papers that cover the new features and enhancements in vSphere 5.1 in a lot more detail than their standard one page overview document that covers them at a high level. These white papers focus on different areas to highlight in-depth what the key changes are in vSphere 5.1 in specific areas that you should know about. This series is a good read so make a pot of coffee or crack open a beer and learn all about the goodness that exists in vSphere 5.1.

2 – Cormac Hogan’s 10-part What’s New in Storage with vSphere 5.1 series

If you don’t know Cormac Hogan, you should, he’s a senior technical marketing architect at VMware and his focus is on storage which he knows a lot about. He produces a lot of great content for VMware on the vSphere Blog and recently started his own personal blog as well which you should definitely bookmark. With each new release of vSphere Cormac does a What’s New series focused on storage and he’s back at it again with vSphere 5.1 which has a number of new storage features and enhancements. By the time you’ve finished reading through his 10 blog posts on storage you’ll probably know as much about storage in vSphere 5.1 as Cormac, well probably not but you’ll still learn a lot.

3 – Derek Seaman’s 13-part series on installing vCenter Server 5.1

Remember back in the good ole days of VirtualCenter 2.5 when everything was all simple, easy and straightforward? Well over time vCenter Server has gotten more and more complicated and installing and configuring it has become no simple task anymore. With so many pieces and parts to vCenter Server now like the Web interface, Update Manager, Single Sign-On, databases, certificates, etc, installing vCenter Server in 5.1 has become complex and occasionally frustrating. Well Derek Seaman has made it easy for you with his epic 13-part mini-series (and counting?) on installing vCenter Server 5.1. This series will guide you through all the different steps of installing vCenter Server and it’s various components and help you avoid any gotchas that you might encounter. vCenter Server should be the first thing you install or upgrade in your environment so be sure and give these a read.

4 – Kendrick Coleman’s video tutorial series on the vCenter Server appliance and the new vSphere Web Client interface

Kendrick Coleman has been a busy boy recording a nice video tutorial series of 11 videos that will get you familiar with deploying the vCenter Server appliance and also familiar with how to perform various tasks using the new vSphere web client interface. Seeing rather than reading can make it easier to learn which is one reason that TrainSignal has become so popular and Kendrick delivers the good with over 2 hours of videos to help make that transition to the new web client interface an easier one. So make yourself a big bowl of popcorn and enjoy these videos on vSphere 5.1 as Kendrick makes a play to win himself a vEmmy award.

5 – Stephen Foskett’s Storage Changes in vSphere 5.1 post

You can never get too much information on storage and Stephen Foskett, the man behind Tech Field Day, puts his own unique spin on the storage changes that are in vSphere 5.1. This has become a tradition for Stephen as he does this with each vSphere release and he provides a lot of great information and insight from his years of experience working with storage. Stephen often seems to come up with those little nuggets of information about storage and vSphere that you won’t find anywhere else so be sure and check him out and I guarantee you’ll walk away learning something new.

6 – VMware’s VMware vSphere Web Client Video Support Series

The days of our beloved (at least for Windows users) vSphere Client are numbered and the future is with the new vSphere Web Client. Making the jump to this new interface can be challenging so luckily VMware has put together a whole video series to show you how to perform various tasks using the new web UI. While us Windows users may put this off and cling to our vSphere Client as long as possible, Linux and Mac fans will rejoice as they can finally natively manage vSphere without having to install Windows. The sooner you get started with the new web UI the better so don’t put it off as you’ll likely not see the vSphere Client in the next major vSphere release.

7 – Vladan Seget’s posts on vSphere Data Protection

vSphere Data Protection (vDP) is a new product introduced with vSphere 5.1 that is based on Avamar from VMware that replaces vSphere Data Recovery (vDR) that was part of the prior vSphere releases. Being a new product it can be a challenge to learn it and understand how it works. Well Vladan who blogs from the tropical beaches of Reunion Island in the Indian Ocean has made it easier for you with a series of posts and videos that will help you get started and comfortable with it. Once you’ve  kicked the tires with vDP and seen how it works you might find yourself desiring a better backup product like Veeam Backup & Replication instead, but hey at least you gave vDP a shot and Vladan is your man to guide you through it.

8 – Chris Wahl’s New 5.1 Distributed Switch Features

A lot of focus is given to storage in each vSphere release but networking sees it’s fair share of new features and enhancements as well. Chris Wahl has done a series of nice posts that cover a lot of the networking stuff that is new in vSphere 5.1. Networking in vSphere can quickly get overwhelming with all those complicated features, layers, packets, ports, switches and acronyms so reading through these posts might make it easier to digest. Even if you’re not a networking person it’s still good to know something about it so be sure and give them a read. For some  information on VXLAN be sure and read Duncan’s posts as well, but heck you probably already have since everyone reads Duncan’s blog.

9 – vSphere 5 Licensing, Pricing & Packaging

Another year, another licensing change. VMware’s infamous vTax went over as well as a fart in a spacesuit so VMware has had yet enough licensing change with vSphere 5.1. In addition they have changed feature availability in editions, introduced new cloud suites, eliminated per VM pricing and much more. So what you know about VMware’s licensing has probably all changed so it’s time to study up on it again and figure it all out. Be sure and hurry up and learn it before it all changes again.

10 – RTFM

I shouldn’t have to tell you this but I will, reading the fricking manuals can really be helpful. I know most of us don’t like to read manuals and just want to dive into playing with the products but VMware actually makes some really good documentation that is more than just your typical step-by-step instructions. I highly encourage you to checkout the separate documentation on Networking, Storage, SecurityAvailability, Resource Management and Performance. These are great guides for learning about the technology and getting some deep dive information on it. VMware even makes it easier for you by putting it in multiple formats such as html, pdf, epub and mobi so you can download it to your device of choice and carry it around with you. Maybe some day they’ll even put it in audio book format so you can listen to James Earl Jones tell you how to configure Storage I/O Control while driving to work, how cool would that be.

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So there you have it, the top 10 things you should read about vSphere 5.1, I’m sure I missed some other great ones as well so feel free to shout out in the comments some additional links that you feel people must read. Also be sure and bookmark my vSphere 5.1 Link-o-rama, new links are added daily and you will find almost everything you need there to get you going with vSphere 5.1.