App Volumes: Reprovisioning fails with AppStacks set to computer based assignments

Linked clone virtual machines provisioning tasks fails.
Recompose fails due to customization failing to join the desktops to domain.
This issue occurs due to AppStacks being attached during the domain join process.

On reboot after domain join c:\svroot cache is cleared losing changes to the VM.

To resolve this issue, disable the App Volumes Service on the parent virtual machine.
Open a command prompt as administrator and run the following commands
sc config "svservice" start= disabled
net stop "App Volumes Service"
ipconfig /release
Shutdown the virtual machine and take a snapshot.

Create a script or batch file as below to set the service to automatic and start the service.
sc config "svservice" start= auto
net start "App Volumes Service"

Copy the script to the parent virtual machine to a directory you can reference later.
In View Administration portal you will have to reference your post-synchronization script:

Open up View Administration Portal
Go to Catalog – Desktop Pools – Select your pool
Click Edit
Select Guest Customization Tab
Enter the file path for script in post-synchronization script name:


Recompose the pool
VMware KB 2147910


The Impact On App Layering On Your VDI Environment

I was testing instant clones in Horizon 7 and it was pretty much a requirement to use some form of application virtualization and get your user data stored off the desktops. My decision on what to select for for testing was based on that I had already had ProfileUnity from Liquidware Labs and App Volumes is bundled in View at the higher layers. I wanted to see the impact of layering on CPU and login times. I has also used UberAgent to collect some of the results. While testing I would run one test run with UberAgent to collect login times and then one with UberAgent agent turned off to collect CPU metrics.

I used three separate applications, each in their own layer.

* Gimp 2.8
* iTunes 10

I used AppVolumes 2.11 since 3.0 is kind of dead in the water and not recommend for existing customers so I can’t see a lot of people using it till the next release. ProUnity was version 6.5

I first did a base run with no App Stacks or Flex Apps but with a roaming profile being stored on Acropolis File Services. The desktops were running horizon 7 agent and office 2013 and were instant clones. The desktops were Windows 10 with 2 vCPU and 2 GB of RAM. When you see the % listed is a factor of both CPUs.

Base Run

So not to bad 14 secs login, probably some clean up I could do to make it faster but also not that realistic if your thinking about enterprise desktop so I was happy with this.

I did test with 1 layer at a time until I used all of the 3 applications. There was a gradual increase in CPU and login time for each layer. The CPU cost comes from the agent and attaching the vmdk to the desktop.

App Volumes with 3 AppStacks


So with 3 layers the CPU jumped by ~20% and the login time went up ~9 secs with App Volumes.

3 Flex Apps



With 3 Flex Apps CPU jumped a bit and login times went up ~4 sec.

Overall Review


What does this all mean?

Well if you have users that only disconnect and reconnect and rarely log out then this means absolutely nothing for the most part. If you have a user base that gets fresh new desktops all of the time and things like large shift changes then it means your densities will go down. I like to say “Looking is for free, and touching is going to cost you”. Overall I still feel this is a small price to pay to have a successful VDI deployment and layering will help out the process.


Best Practices with 3D Graphics For VMware View 6.2

Don’t use vSGA with 4K monitors
When 4K monitors are configured on machines where 3D Rendering and vSGA are enabled, moving, resizing the Windows Media Player window to full screen mode can be very slow. This issue does not occur with 2D, software 3D Rendering, or monitors with 2560×1440 resolution.

Have different templates for NVIDA support and non-gpu deskops
If NVIDIA drivers are installed on a virtual machine that you use as a parent or template to deploy a desktop pool, and the machines are deployed on non-NVIDIA GRID hardware on the ESXi hosts, users might not be able to start desktop sessions correctly. This issue might occur if the virtual machine was used previously in an NVIDIA GRID vGPU deployment. Remove the NVIDIA drivers from the virtual machine before you take a snapshot or make a template and deploy the desktop pool.

Use the latest NVIDIA drivers
If vDGA is enabled on a Windows 7 virtual machine that is configured to use NVIDIA driver version 347.25, the desktop session can be disconnected. This issue does not occur on Windows 8.1 or on other NVIDIA driver versions. Do not use NVIDIA driver version 347.25.

Disable screen savers or use a black screen
On Windows 8/8.1 desktops, 3D screensavers operate even when the 3D Renderer setting is disabled, and the screensavers do not render correctly. This issue does not occur on Windows 7 desktops.
Workaround: Make sure your end users do not use 3D screensavers, or enable the 3D Renderer setting for the desktop pool.

Remove old NVIDIA vibs before upgrading
Check to see if you have an old NVIDIA vib before upgrading. You might be not be able to power on your desktop.

esxcli software vib list | grep NVIDIA

Reserve all your desktop memory


GPU-Z for XenApp / RSDH (View)

GPU-Z is a PC graphics diagnostic and monitoring utility, which gives you up to date information of the GPUs installed in your system, and lets you monitor their clock speeds, temperatures, fan-speeds, voltages, dedicated and memory usage. It’s a perfect tool to be using in your XenApp and RDSH farms depending on your broker of choice when using a GPU.


< download GPU-Z >


VMware Horizon 6 RDS-hosted Apps and Imprivata failover with New Firmware

PCoIP Firmware 4.8.0 firmware for Tera2 zero clients has just been released. Some small goodies in there but I think the main one is for RDS. Zero clients now support VMware Horizon 6 application remoting based on Microsoft Remote Desktop Services (RDS). To configure zero clients to access VMware Horizon streamed applications, select the new Enable RDS Application Access option on the View Connection Server > Session page, under Advanced Options.

The new firmware aslo allows a View Connection Server address for Imprivata OneSign environments allows administrators to configure a Direct to View link on zero clients configured for View Connection Server + Imprivata OneSign mode. When users click the link, the current OneSign connection or authentication flow is cancelled and a Horizon View authentication flow starts instead. This feature lets OneSign zero client users access their View desktops when the OneSign infrastructure is unavailable.

—- link to new firmware —-



Pay-As-You-Grow with Nutanix and VMware Horizon 6

Dwayne Lessner
Technical Marketing Engineer, Nutanix

As an end user of VMware End User Computing (EUC) products since 2008 when the product was called Virtual Desktop Manager 2.1, it’s been a great journey to see how VMware Horizon 6 with View has morphed into a full fledge application delivery platform. The latest version of Horizon offering the ability to deliver virtual desktops and hosted applications with Microsoft Windows Remote Desktop Services arms businesses with the right deployment method based on use case and cost.

Today customers can take VMware’s EUC strategy and deploy with the same speed and approach of Public Cloud Providers with the security and control over SLA’s in the comfort of their own datacenters. Nutanix with the support VMware is proud to release our latest Reference Architecture on VMware Horizon 6 with View that showcases benefits of pay-as-you-grow infrastructure.

Some of the highlights include:

Nutanix and VMware EUC customers like Serco and Langs Building Supplies enjoy flexible, fast and simple deployments without making concessions for reliability or performance. Nutanix customers can embrace the blend of convergence and web-scale technologies to focus on deploying applications on their own terms.

Read the full reference architecture with Horizon 6 with View on Nutanix and stop by booth #1535 at VMworld to learn about new features that Nutanix and VMware EUC is bringing to the datacenter.

This has been cross posted on Nutanix.com & VMware.com


VMware Horizon 6 with View – Hosted Shared Virtual Desktops with Nutanix

With Horizon 6 adding support for RDS, Application pools is getting a lot of buzz. With application pools, you can deliver a single application to many users. The application runs on a farm of RDS hosts. However, you can use a farm of hosts to deliver hosted shared desktops (HSVD). I suspect in reality this will shift lots of workload over at least from the task worker use case.

To get HSVD setup with Horizon 6 you have to:

Once the farm is created you can go to desktop pools and pick the appropriate option.

Nutanix Value

1) Quick Clones\VMCaliber Clones – Horizon 6 does not support View Composer for RDS so there could be a potential for lots of storage to be gobbled up. VMCaliber Clones have no negative impact on performance, allow for fast deployment and is available in every Nutanix software edition.

Check out the space saving from quick clones. 84 GB to 12KB

Check out the space saving from quick clones. 84 GB to 12KB

2) Data Locality & Fair Share – Fair Share from 2012 R2 to gives predictable user experience so one user does not negatively impact the performance of another user’s session. Combined with data locality as the cluster scales, IO performance will be consistent and not users can’t steal or bleed the rest of the performance from users on other nodes.

3) Tunable Redundancy Factor – Starting with the Pro Software Edition and up you can allow VM’s to have greater resiliency by creating additional copies of data. Since VMCaliber clones(per vm snaphots\clones) are reducing the foot print the added capacity cost of higher Replication Factor will be mitigated. Now you can lose up to 2 nodes on a 5 node cluster as an example without having to buy additional HDD’s for capacity. Additional block awareness can let you lose an entire block (4 nodes/servers) at the same time without downtime, without requiring any extra space! This all adds up to more capacity for other server workloads in your environment.

Hope see you at VMworld 2014 and talk more on this topic.



VMware Horizon View 6: Cloud Pods & Windows 2012R2

Only getting accepted into the beta the evening before the NDA was lifted it’s not like I had a lot of time to see and test everything. RDSH support is getting all of the hoopula but for me I had two bucket list items that finally saw the light of day.

The big one for me for was Horizon View Cloud Pod. I’ve been waiting a long time to see this come out because it was a problem I self inflected my former employer with in 2009. I still see lots of people wanting to stretch their View Connection Servers across sites which is a no no due to the java messaging service that needs less than 4 ms to maintain good behavior. Now you can have 4 pods, across two sites, servicing 20,000 users.

Cloud Pod

Cloud Pod

The first glimpse of this came two VMworlds ago, Demystifying Large Scale Enterprise View Architecture: Illustrated with Lighthouse Case Studies with John Dodge. Active\Active DR made easy. F5 and NetScalar still have a place to play but I am not sure yet.

You can assign a sites to your pods and users can have a home site. A home site is the affinity between a user and a Cloud Pod Architecture site. Home sites ensure that users always receive desktops from a particular datacenter, even when they are traveling. If a home site is not setup the Cloud
Pod Architecture feature delivers the nearest available desktop in the pod federation. If all of the desktops in the local datacenter are in use, the Cloud Pod Architecture feature selects a desktop from the other datacenter.

The 2nd great thing is support for Active Directory Domain Services domain functional levels for 2012\2012R2. You can finally install the connection server on 2012\2012R2.

Great day for VMware View shops


W5 of Using VMware View Planner: Complete Setup

by Tony Holland Senior SE Nutanix @tonyholland00

Have you ever wanted to test a VDI workload to see what it looks like? If you have, then I would highly recommend looking at VMware View Planner.

I have been working with VMware View Planner since its inception with View Planner 1.0. It was a very primitive tool at the time, but having a tool to simulate what an actual VDI user typically does throughout the day is a very hard thing to come by. Who doesn’t have hundreds or thousands of users at your beck and call to test with? VMware View Planner provides exactly that. The primary users of VDI workload generation tools are hardware vendors. Hardware vendors do not have 100-1000’s of users to test with so they are forced into using synthetic tools to simulate the workload. The workload generated will not match your companies user workload, but it does provide us (Nutanix) and all other hardware players the exact same test to run over and over to find the breaking points / bottlenecks in our solutions. It is not a sizing tool!!

To acquire VMware View Planner you need to talk with a VMware partner. The download for the version of VMware View Planner 3.0 is only available though VMware Partner Central.

One key point that many IT administrators don’t understand about View Planner is that it should not be used as a sizing guideline for how many VDI users you can run on existing or new hardware. View Planner does a great job of simulating the workload of a VDI user but I have yet to see a single company that has a VDI image / template exactly like the one used by View Planner. I also have never seen a company that all users do the exact same thing for hours on end. If you want to size how many actual users you will be able to run, you should use a real user. Pick a handful of people to deploy a VDI desktop to and run a very small pilot. Use your corporate image/template to build the VDI desktops and have actual users work off those VDI desktops. Collect Read-Write IOPS, CPU and Memory data used per user during the pilot and extrapolate that data to figure out the correct amount of users your environment can handle. Don’t forget about N+1. View Planner should be utilized to simulate a synthetic VDI workload that can help find the bottlenecks in your hardware.

Another great thing about View Planner is that you can use it with other VDI technologies not just VMware View. If you follow my directions below you can utilize any VDI servicing apps such as XenDesktop or VMware View to create the desktop pools. I love this because I can test all the features, for example…VMware Storage accelerator, VMware VCAI, Citrix MC or PVS. The only things required for VMware View Planner are the ESXi hypervisor and vCenter. A simple Powershell script could also spin up the required number of desktops to do a View Planner run.

While View Planner does a nice job simulating VDI workloads, it does not take breaks. Think about your office, how often do you see people flirting with co-workers, chit-chatting on phone, going on a smoke breaks and impromptu meetings. With View Planner testing 100 or 1000 desktops in those 3-5 hours while you run the 5 iterations, those 100-1000 VDI desktops will be working/running 100% of the time – no potty breaks. This phenomenon of 100% of your users working simultaneously, not only will never happen but it also will cause the user density number to be skewed. Planning for 80% concurrency is probably more realistic.

Why use VMware View Planner in local only mode? To me the local only mode is very simple, it uses the least amount of infrastructure, resources, and gets IT administrators the data that they are yearning for. Again, it is not a sizing tool, but it is a great load (IOPS and CPU/Memory) generation tool. Utilizing remote mode you are testing the PCoIP protocol. PCoIP typically is not the issue when dealing in a LAN environment IOPS, CPU and memory are. So in my opinion adding extra complexity and hardware to have virtual client desktops launching a bunch of View sessions is unnecessary to get the data that most IT admin’s are looking for.

If View Planner looks like a tool that would be beneficial to you here are some prerequisites :

• View Planner 3.0 (Talk to your VMware partner)
• Microsoft Office with Volume Licensing 2007 or 2010 with no service packs and only (32-bit)
• Microsoft Internet Explorer version 8.x or 9.x.
• Mozilla Firefox version 3.6.x, version 4.0.x, version 5.0.x, version 6.0.x, or version 7.0.x
• Adobe Reader version 9.x or version 10.x (also called Adobe Reader X) on each desktop virtual machine.
You will find all of the instructions on how to install the applications in the View Planner User Guide page 78
• ESXi hosts 5.0, 5.1 or 5.5 to run View Planner appliance and the VDI Desktop VM’s
• VMware vCenter

Steps to setup View Planner

• Download the View Planner OVF from VMware Partner Central
• Download Planner Documentation from Partner Central
• Deploy OVF of View Planner on an ESXi host… Follow View Planner User Guide p.35
• Login to View Planner appliance web page (Username: root Password: abc123) and configure your vCenter IP, and credentials and
vCenter VDI Cluster Datacenter… Follow View Planner User Guide p.38
• Create a new VDI Desktop template Windows XP, 7 or 8 VM named “GoldTemplate”…Follow the View Planner Users Guide p.65
• Install template desktop OS using a VL MAK or KMS key KMS is preferred (XP, Windows 7 or 8)… Follow the View Planner Users Guide p.68 instructions for “Installing Applications in Desktop Virtual Machine”

Complete View Planner User Guide Documentation Sections
• Create the Desktop Template Virtual Machines…p. 65
• Install Microsoft Windows in the Template Virtual Machine…p. 68
• Install the VMware Tools Suite in Microsoft Windows…p. 72
• Add a Data Disk to the Desktop Virtual Machine…p. 75
• Go into Computer Management and Manage the local user accounts. You will need to enable the Administrator account and assign the password of Q1w2e3r4!
• Reboot computer and login as Administrator and password Q1w2e3r4!
• Continue to follow the View Planner guide on installing applications in Desktop Virtual Machine…. p. 78

Complete View Planner Documentation Sections
• Install Applications in the Desktop Template Virtual Machine…. p. 78
• Enable Pseudo Perfcounter for the Virtual Machine…. p. 79
• Install Windows Updates…. p. 80
• Add the Desktop Template Virtual Machine to the Dedicated Domain…. p. 82
• Install the View Agent…. p. 85
• Take a Snapshot of the Virtual Machine…. p. 85
• Download and Install the View Planner Workload Support File…. p. 86
• Shutdown

Now you can start to follow my directions as View Planner documentation and I go about things a little differently.

• Startup your View Planner Desktop template it should auto -login and you should notice a cmd window bat file running in the background.


• Browse C:\ drive of the View Planner Desktop template. Notice the IP.txt file. The only line needed is the harnessIP=.
** – If you do not see IP.txt your installation of the View Planner desktop files did not complete successfully. Manually create the file if need be, but their could be
other problems with the template install. I would attempt to uninstall and reinstall the View Planner desktop files. If all else fails go back to snapshot taken before this step.


Pre View Planner Template Checkup
• Check to make sure that the Windows Firewall is disabled
• Startup all apps, Word, Excel, Powerpoint, Adobe, Firefox, IE and make sure that no extra windows pop up when the app is running.
• Shutdown the GoldTemplate VM.
• Login to View Planner Appliance web page (username: root password: abc123)
• Under Run & Reports tab click on New under Run Profiles
• Fill out Profile Name: Test-1VM
• Number of VM’s: 1
• Desktop Name Prefix: GoldTemplate
• RampupTime:5
• Test Type: Local
• AD Group Settings: Name: Test | Workload Profile: Choose the StandardBenchmarkProfile_1i | % VMs: 100
• Click Save
• Login to the View Planner Appliance via SSH via Putty or a SSH client (username: root password: vmware)
• Change directory to /ViewPlanner
• Tail -f viewplanner.log
• Go back to the View Planner Appliance webpage
• Under Run & Reports tab click on the run profiles and click on the newly created Test-1VM
• Click on Run
• This will start the View Planner process on the VM call GoldTemplate
• Monitor the viewplanner.log via the SSH session. You should see View Planner scan all VM’s to find a match to “GoldTemplate”


• View Planner appliance will tell vCenter to start the VM “GoldTemplate” and View Planner will wait for the guest to register or (check in) with the View Planner appliance.
• Open the VM Console view of “GoldTemplate” from vCenter and watch View Planner startup and run the applications.


• Make sure that all apps open correctly and that no extra pop up windows appear.
• After around 20-30 minutes you will see that the workload was successfully uploaded to View Planner
• Look at the viewplanner.log screen on the SSH session. You should see a message indicating that the test was complete.
** Couple of things to watch for here…
If you used Office x64 View Planner will stall on MS Word and not work
If you don’t have the correct HarnessIP in the IP.txt file you will never connect to the View Planner appliance and the workload will not start.
Windows Firewall will also get in the way. Be sure that firewall is disabled after you added the computer to the domain.


• Properly Shutdown GoldTemplate VM
• Create a final snapshot of the GoldTemplate VM called TestedViewPlannerSetup (Use this snapshot with VMware View Linked Clones)
• You can also now delete the snapshot created before as you have now validated that your desktop is ready to go!

Creating Desktops via VMware View 5.3

I utilize VMware View to create the desktops for my View Planner runs. You can use whatever technology you prefer when creating these pools. Even Xendeskop will work!!! In this use case I am going to create non-persistent Dedicated pool with VMware View Linked Clones.

• In VMware View add a new Pool
• Type “Automated Pool”
• User assignment “Dedicated”
• View Composer Linked Clones
• Pool ID: Pool1
• Pool Settings: I leave the defaults PCoIP will not be used so these settings are not really relevant
• Provisioning Settings: Enable Provisioning; Disable Stop provisioning on error
• Virtual Machine Naming: Use Naming Pattern: VDI-P1-
• Pool Sizing: X amount of desktops you want to create
• Provisioning Timing: Provision All Desktops up front
• View Composer Disks: Redirect disks if you would like I typically choose not to for this test
• Storage Optimization: For Nutanix you should never separate Replica and OS disk other technologies you might want to choose this option
• vCenter Settings: Choose your Parent VM: GoldTemplate
Choose Snapshot: TestedViewPlannerSetup
VM Folder: Your Choice
Host or Cluster: Hosts running Guests
Resource Pool: Your Choice
Datastore: Choose Datastore to provision Pool desktops onto. Nutanix should typically only have one Datastore.
• Advanced Storage Settings
• Use View Storage Accelerator: Optional (Adds provisioning time)
• Use NFS Snapshots: Optional again speeds up provisioning
• Click Finish to create the pool!!

• Once provisioning has completed and all desktops are fully provisioned clicking on desktops in VMware View should like out all of the newly created VM’s. All desktops should have a status of “Provisioned” and a DNS name.


• After all desktops are successfully provisioned and DNS assigned Disable the VMware Pool.
By disabling the pool you remove VMware View from controlling the desktops. If you leave the pool enabled and shutdown all VM’s to prepare for the View Planner run, View will automatically power on the VM’s which in production is a great thing, but in this use case having vCenter control all of the power on and power off’s. From this stage forward we will use View Planner and vCenter to power on and off the desktop’s. Thanks for doing all that work View but we are done with you for now!

Prepare Desktops for View Planner Run

• Using vCenter go to the cluster object and click on the Virtual Machine tab. Sort VM’s by name. You should be able to highlight all powered on VM’s and select the Shut Down Guest OS option. This will cleanly shut down all of your desktop VM’s to prepare for View Planner run. I typically create a few powershell scripts that will do this by Name if you are working with more than 100 or so guests.

• Login to the View Planner appliance via SSH via Putty or SSH client of choice.

• Change directoy to ViewPlanner
• Cd /ViewPlanner
• Edit the adminops.cfg file
• vi adminops.cfg
• Press the i key for insert mode.


• I typically change this to 32 or a lesser number as this can create a fairly large bootstorm. If only a few hundred users you can probably leave at 64. This is also a fun parameter to play with to see how a boot storm can effect the environment.
• Edit to 32 or whatever value you would like to set
• Press esc key
• :wq! (this will write changes to the adminops.cfg file)

• Reboot View Planner appliance VM

Run a View Planner Test

• Using vCenter perform a proper shutdown of all VDI guests that you want to run View Planner on.
• Login to the web console of the View Planner Appliance
• Under the Run & Reports Tab create a New Run Profile.


• Fill out Profile Name: Production-Run
• Number of VM’s: 100 or however many VM’s you want to test
• Desktop Name Prefix: VDI-P1- (use the name scheme that you used to create your VDI Pool in View)
• Ramp up Time:(will populate automatically based on # of VM’s)
• Test Type: Local
• AD Group Settings: Name: Test | Workload Profile: Choose the StandardBenchmarkProfile_5i | % VMs: 100 click Add Group
• Save
• Login via SSH to View Planner Appliance (username: root password: vmware)
• Change directory to /ViewPlanner
• tail -f viewplanner.log
• Switch back to the VMware View Planner webconsole
• Select you newly created Run Profile “Production-Run”
• Click on Run

• Notice vCenter starting to power on all of your desktopsin the viewplanner.log. This is a great place to watch what is exactly happening with the View Planner run.


• After all desktops are powered on and all checked in View Planner will attempt to resolve IP Address for each desktop via VMware tools.


• After successful IP address resolution View Planner will take a moment to rest(Ramp Up Time) before it starts to tell the VM’s to begin the workload.


• The workload will then be started on each desktop machine. You should see CPU and memory usage start to increase on the ESXi host(s).

The test will now run though 5 iterations. Which means it will do 5 loops of the test. If you want more iterations to see how your storage handles it simply adjust that in the View Planner run profile. I have set iterations to 5000 so it would start and run for days to see how everything handled it.

This is fun time for an IT administrator. Once the test is started utilize ESXTOP take a look at IOPS (cmds) and latency. Look in vCenter at CPU and RAM consumption. Look at Datastore latency from vCenter……It is like Christmas with data.




• Once CPU, memory and IOPS drop off you can make a safe guess that the View Planner test is completed.
• Checkout the viewplanner.log via the SSH
• Also have a look in the Web Console. You should see the Run Successful


• Now that you have completed a successful View Planner run you will have all sorts of great information.
• I typically will go and shutdown all of my guests as a first step after confirmation that the test was a success. Even if the test was not a success you will want to properly shutdown the guest VM’s to get them ready for another run.
• If you want to test something thing different, delete the Pool in View or simply recompose the desktops. Just remember to disable the pool after you finish the creation as View will continually startup VM’s.

I also wanted to give a shout out to Banit Agrawal from VMware who has helped me out with View Planner from the 1.0 days. Thank you for all of the assistance. I hope this post will help a few others learn from some of the mistakes and stumbles that I had during my time working with View Planner.

Thank you for reading, I hope that this will help understand the use cases for and against synthetic workload testing. If you have questions please don’t hesitate to reach out over twitter. @tonyholland00


Nutanix Cache Money: When to Spend, When to Save

Spend wisely

Spend wisely

Every Nutanix virtual storage controller has local cache to server the workloads running directly on the nodes. A question that comes up is if the local cache should be increased. No ever complained about having too much cache but being a hyper converged appliance we want to keep the RAM available for the running workloads if needed. I would never just recommend giving every controller virtual machine(CVM) 50 GB or 80 GB of RAM and see where that gets you.

The cache on the CVM is automatically adjusted when the RAM of the CVM is increased. I recommend increasing the CVM memory in 2 GB increments and track the effectiveness of the change. Even starting with 16 GB of RAM in a system that has 256 GB of RAM available is only ~6% of the RAM resources available.

Nutanix CVM Resources starting points




Inline Dedupe

Memory Size

Increase to 16 GB

Increase to 24 GB

Memory Reservation

Increase to 16 GB

Increase to 24 GB

Base (Non-Dedupe)

Go to any CVM IP address and check the startgate diagnostic page http::2009 and use the below guidelines before increasing your RAM on the CVM. You may need to allow access to the 2009 port if you’re accessing the page from a different subnet. This is covered in the setup guide.

Extent Cache

Amount of CVM RAM

Extent Cache Hits

Extent Cache Usage


16 GB

70% – 95%

> 3200 MB

Increase CVM RAM to 18 GB

18 GB

70% – 95%

> 4000 MB

Increase CVM RAM to 20 GB

NOTE: Going higher than 20 GB of RAM on a CVM will automatically start allowing RAM to be used for dedupe. If don’t enable dedupe past 20 GB of RAM you will be wasting RAM resources. You can prevent this from happening by the use of GFLAGs. It’s best to contact support on how to limit RAM being used for dedupe if you feel your workload won’t benefit from it.

Using the Prism UI you can assess if more RAM will help hit rate ratio. Cache from Dedupe is referred to as content cache. The content cache spans over RAM and flash. It is possible to have a high hit rate ratio and have little being served from RAM.

In the Analysis section of the UI check to see how much physical RAM is making up the content cache and what your return on it is.
Screen Shot 2014-02-24 at 4.57.10 PM

If the memory being saved is over 50% of the physical memory being used and the hit rate ratio is above 90%. You can bump up the CVM Memory.

NOTE: For both extent cache and content cache it is possible to have a low hit rate ratio and high usage of resource and still benefit from more RAM. In a really busy system the workload may be too large and might be getting cycled thru the cache before it can hit a consecutive time. It’s our recommendation to increase the CVM memory if you know your maximum limit for CPU on the host. Available memory can help the running workload instead of sitting idle.

Hopefully this helps in giving some context before changing settings in your environment.

Learn more about Nutanix with The Nutanix Bible