OpenStack vs AWS

Service OpenStack Project Name Amazon
Virtual Machines Compute Nova EC2
Virtual Block Devices Block Storage Cinder EBS
Object Storage Object Storage Swift S3
Virtual Networks Networking Neutron (formerly Quantum) VPC
App Orchestration Orchestration Heat CloudFormation
App Monitoring Measurement Ceilometer CloudWatch
Tenant Auth / Namespace Identity Keystone IAM
Boot Images Image Service Glance AMI
GUI Dashboard Horizon Management Console
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Citrix XenDesktop RAM Cache – An awesome way to save your IOPS

We have been fighting storage IO battle since day one. There are many flash technologies on the storage vendor side. Now Citrix Provisioning Service has an awesome and easy to use feature called RAM Cache on the hypervisor RAM that can reduce  storage IO by 90%. RAM cache is great for PVS non-persistent desktops. For MCS or any persistent desktops, RAM cache is not ready yet.

I tested RAM Cache last year. The result was unbelievably good. I shared at NetApp Insight Vegas and Berlin. In January, I attended Dan Feller‘s session “Technical Update for XenApp and XenDesktop – 2015 Edition” at Citrix Summit. Now it is time to promote RAM Cache.

How to use RAM Cache? At PVS console, select vDisk properties and choose Cache type as “Cache in device RAM with overflow on hard disk”. This will use hypervisor RAM first and then use hard disk. Choose the RAM size based on OS type.

RAM sizing consideration

  • 256 MB for Win7 32bit
  • 512 MB for Win7 64bit
  • 2GB-4GB for XenApp VM

More detail on sizing RAM cache, check  Size Matters: PVS RAM Cache Overflow Sizing.  Also as a best practice, defragment the vDisk before deploying the image and after major changes.

ram cache conf

Now let me share the test setup and result:

Physical hardware

Cisco UCS Server CPU:  20 CPUs X 2.799 Ghz   Intel CPU E5-2680 v2@ 2.80GHz

Server RAM:   48 GB

Hypervisor: vSphere 5.5


 NetApp FAS3240 with 2 shelves HDD disks

 VM Configuration

Win7 VM:



VM OS: Windows 7

vDisk: 20GB

VM write cache: 6GB


Load generation tool

LoginVSI 4.1

 Test procedure: 

I ran 4 tests to find out if RAM cache is useful and what is the optimized RAM Cache size compared to Citrix’s recommendation.

1. Baseline without RAM cache

2. With RAM cache size as 256MB

3. With RAM Cache size as 512MB

4. With RAM Cache size as 1GB

Test result: I use NetApp perfstat to capture the write cache NFS volume total IOPS.

ram cache testing

The blue line is the result without RAM Cache. The IO saving is tremendous.

What is the lesson learns?

Increase your write cache when you use RAM Cache

Storage is 4k based and RAM is 64MB. “If transitioning an environment from Cache on HDD to Cache in RAM with overflow to disk and the RAM buffer is not increased from the 64MB default setting, allocate twice as much space to the write cache as a rule of thumb.”

Different performance on different hypervisor 

Reduce storage IO. The data is from Dan Feller’s deck at Citrix Summit.

– By 99% with XenDesktop

– By 80% with XenApp on Hyper-V

– By 24% with XenApp on vSphere

Defragment your vDisk to save your write cache size

“Defragmenting the vDisk resulted in write cache savings of up to 30% or more during testing.”



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Hope I can meet you at Vegas!

Hope you are as excited as we are for Insight 2014 Las Vegas! I will have 6 NetApp break sessions and a XenDesktop on Hyper-V lab. This will keep me busy.  Also you can find me at virtualization booth.  Hope I can meet you in Vegas!

MB-1-2025 – Citrix ShareFile Data Mobility for Enterprise
Date/Time: Tuesday, 10/28/14, from 13:30 to 14:30

MB-1-2025 – Citrix ShareFile Data Mobility for Enterprise
Date/Time: Wednesday, 10/29/14, from 14:45 to 15:45

VI-3-2132-TT – Citrix, VMware, and All-Flash FAS: A Reference Architecture Deep Dive
Date/Time: Monday, 10/27/14, from 13:00 to 15:15

VI-2-2024 – VDI Design, Architecture, and Best Practices for Citrix and VMware
Date/Time: Tuesday, 10/28/14, from 16:15 to 17:15

VI-3-2132-TT – Citrix, VMware, and All-Flash FAS: A Reference Architecture Deep Dive
Date/Time: Tuesday, 10/28/14, from 11:15 to 13:30

VI-2-2024 – VDI Design, Architecture, and Best Practices for Citrix and VMware
Date/Time: Wednesday, 10/29/14, from 16:15 to 17:15

VI-3-2132-TT – Citrix, VMware, and All-Flash FAS: A Reference Architecture Deep Dive
Date/Time: Thursday, 10/30/14, from 11:00 to 13:15


Screenshot 2014-10-24 10.55.10

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Citrix XenDesktop Design Guide is published

Design guide for Citrix XenDesktop on NetApp Storage is published today. The Citrix XenDesktop 7.5 system, which now incorporates both traditional, hosted Windows 7 or Windows 8 virtual desktops, hosted applications, and hosted shared Windows Server 2008 R2 or Windows Server 2012 R2 server desktops (formerly delivered by Citrix XenApp) provides unparalleled scale and management simplicity while extending the Citrix HDX FlexCast models to mobile devices.

NetApp clustered Data ONTAP—with its key capabilities such as nondisruptive operations, unified storage, multiprotocol architecture, secure multi-tenancy, storage efficiency, read and write performance, and cost efficient data protection—is ideal for cost-effectively designing and deploying end-to-end storage solutions for desktop virtualization based on a single or mix of various XenDesktop FlexCast models.

This technical report provides key storage design and architecture best practices for deploying a mix of FlexCast technologies on a NetApp clustered Data ONTAP storage array. It also includes performance testing results and solution scalability guidelines that prove that NetApp clustered Data ONTAP can cost effectively scale to thousands of desktops without adding complexity.

Screenshot 2014-10-23 12.51.31

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Big Hammer for virtual desktop

As a solution architect in a storage company, I am often asked by customers and sales engineers how many IOPS per desktop. My answer is always it depends. Virtual desktop IOPS is a myth. It varies by application, the stage of the workload, provisioning methods, and hypervisors. VDI IOPS is like different size nails, some are small like 2-3 IOPS per desktop, some are big like 20-30 IOPS. The easiest way is to have a big hammer to be able to hit nails in all size.  NetApp finally revealed all flash FAS ( AFF), the big hammer.



NetApp offers All-Flash  with advanced data management delivering high performance, advanced data management, and low cost per desktop. The NetApp All-Flash FAS solution shares the same unified storage architecture, Data ONTAP OS, management interface, rich data services and advanced feature sets as the Hybrid-FAS solution. This unique combination of All-flash media with Data ONTAP delivers the consistent ultra-low latency and high IOPS of all-flash storage, with the industry-leading clustered Data ONTAP OS. In addition, it offers proven enterprise availability, reliability and scalability; storage efficiency proven in thousands of VDI deployments; unified storage with multiprotocol access; advanced data services; and operational agility through tight application integrations.

We recommend to use AFF when the IOPS is > 20IOPS per desktop or ultra low latency  like < 1ms is required.

Check our new reference architecture on All flash FAS with VMWare View. AFF with XenDesktop is coming in a couple of months. Yes, I am doing the work.  🙂

Screen Shot 2014-06-24 at 11.04.46 PM

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Citrix Synergy 2014

I am excited to go to Citrix Synergy every year. It is a time to get to hear what Citrix is going to say about  virtual desktop, cloud and data mobility. Also it is always so good to meet my Citrix friends.

I will present  M320 Accelerating Virtual Desktop with NetApp on Thursday May 8th at 9:30 Room with Mr. Cooper. The session will cover 3 topics: Clustered Data OnTAP with vSphere 5.1 and XenDesktop 7.1 CVD, $35 dollar per desktop Citrix ready VDI capacity program and NetApp flash technology – All Flash FAS8000.

Screen Shot 2014-05-01 at 11.49.15 AM


We also have some great breakout sessions planned that will go deeper into the technology:

  • “How to Build a Standardized Cloud Architecture with XenDesktop and NetApp Storage”
  • “How to Best Utilize Citrix ShareFile on NetApp”

Finally, here’s a sneak peak at our booth mini-theatre sessions:

Screen Shot 2014-05-01 at 1.36.31 PM Screen Shot 2014-05-01 at 1.36.19 PM Screen Shot 2014-05-01 at 1.36.05 PM

Come by booth 201 to see our demos, meet executives, talk to customers, and mingle with technical experts.

I am looking forward to seeing you in Anaheim.




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$37 per Desktop for storage: Citrix Ready VDI Capacity Program

Citrix Ready VDI Capacity Program 

Citrix Ready has created an opportunity for storage partners representing several different VDI storage options to plug their storage solutions into a turnkey “VDI Capacity” test environment located in our Santa Clara, CA solutions lab. This program was created with two goals in mind:

  •   Meet a defined VDI storage workload without reaching storage latency thresholds
  •   Do so with a cost- effective design

As part of this Citrix program, NetApp joined Citrix at their Solutions Lab in early 2014 to stress test a NetApp FAS2240-2 hybrid storage array. The stress testing took place against a 750 seat desktop virtualization environment based on Citrix XenDesktop 7.1. The end goal was to prove NetApp can deliver a storage solution at a very economical end user storage cost of $37 per desktop.

Screen Shot 2014-04-16 at 3.23.00 PM

What’s included?

–NetApp Storage HW (FAS2240-2)

–24 internal HDDs(600GB SAS, 10k RPM)

–NetApp SW licenses (iSCSI and CIFS)

–36 months, NetApp 24×7 premium support, w/ 4 hour parts replacement

 Storage ArchitectureScreen Shot 2014-04-15 at 3.46.03 PM

The NetApp FAS2240-2 was completely configured and setup in under two hours. Below is an outline of the entire NetApp storage solution configuration.

  • NetApp Clustered Data ONTAP® 8.2 operating system
  • Dual controllers with active/standby configuration. This configuration ensured high IOPS for boot, login, and steady state operations as well as consistent high performance for end users in case one storage controller fails
  • Each controller has 2 10GbE ports and x FC ports that can be used for data and cluster interconnect. For this test setup, each controller was configured with:
    • 1 x 10GbE Cluster inter-connect for HA
    • 1 x 10GbE iSCSI Data Logical Interface (LIF) per controller with LIF migration established for HA
    • Jumbo Frames were not used for the iSCSI Data LIFs in this test scenario
  • The 24 HDDs were configured as such:
    • Active Controller:
        • 16+2 RAID DP® configured for the main data Aggregate (16 data drives and 2 for parity) hosting the virtual machines
        • 1+1 RAID 4 for the root Data ONTAP® Aggregate
        • 1 Spare Drive
    • Standby Controller:
        • 1+2 RAID DP® for the root Data ONTAP® Aggregate
  • The storage was configured with a single iSCSI clustered Data ONTAP® storage virtual machine (SVM) for hosting the virtual desktops as well as a single SVM for CIFS shares to host user data.
      • iSCSI Virtual Server contained 1 x 11TB Volume
        • 11 x 1TB LUNs created for PVS Write Cache
        • Each LUN was attached to a unique Hyper-V host which contained 85 virtual desktops booting from Citrix PVS.
      • CIFS Virtual server contained 1 x 22TB Volume
        • 1 x 22TB share created for user data

Test results:

  • Boot and Login Storms
      • 935 users boot and login < than 20 minutes
  • Steady state
      • 750 users, VSI Max NOT  reached during test

The environment could have supported around 800 virtual desktops.

Screen Shot 2014-04-16 at 3.55.47 PM

For customers looking for an efficient, scalable, and resilient XenDesktop deployment under 1000 seats, the NetAppFAS2240-2 based storage solution excels at providing substantial performance, density and scalability at a very affordable $37/desktop. Through this Citrix Ready validation program, NetApp has demonstrated the ability to deliver a cost effective virtual desktop that provides a better user experience without impacting overall performance, scalability, or manageability. With the capability to run 750 desktops from a 2 rack unit hybrid storage array and the ability to scale without disruption to operations, this solution can be used by both small businesses and large enterprises. NetApp provides an outstanding solution for your desktop virtualization needs.


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CVD: FlexPod Reference Architecture for a 2000 Seat Virtual Desktop Infrastructure with Citrix XenDesktop 7.1 on VMware vSphere 5.1: Storage

Two nodes FAS3240 with 4 shelves DS2246 were utilized in the deployment to support 1450 users of hosted shared desktops (HSD) and 550 users of hosted VDI (HVD). Clustered Data ONTAP version is 8.2P4.

To support the differing security, backup, performance, and data sharing needs of users, we group the physical data storage resources on your storage system into one or more aggregates. You can design and configure your aggregates to provide the appropriate level of performance and redundancy for your storage requirements. For information about best practices for working with aggregates, see Technical Report 3437: Storage Subsystem Resiliency Guide.  This design I used one aggregate per node since this is one deployment and with 2 shelves per node.

You create an aggregate to provide storage to one or more volumes. Aggregates are a physical storage object; they are associated with a specific node in the cluster.

The following table contains all aggregate configuration information. NetApp uses 3 disks for root aggregate as default.

Screen Shot 2014-03-06 at 10.06.56 AM

Volumes are data containers that enable you to partition and manage your data. Volumes are the highest-level logical storage objects. Unlike aggregates, which are composed of physical storage resources, volumes are completely logical objects. Understanding the types of volumes and their associated capabilities enables you to design your storage architecture for maximum storage efficiency and ease of administration.

A FlexVol volume is a data container associated with a virtual storage machine with FlexVol volumes. It gets its storage from a single associated aggregate, which it might share with other FlexVol volumes or Infinite Volumes. It can be used to contain files in a NAS environment, or LUNs in a SAN environment.

The following table lists the FlexVol configuration.

Screen Shot 2014-03-06 at 10.10.27 AM

The following diagram explains the storage layout.

725 RDS user write cache is on node 1. 725 RDS user and 550 HVD user write cache is on node 2. Two CIFS virtual storage servers are created for HSD and HVD users are created on each storage node. VMware ESXi 5.1 SAN boot volume is on node 1 and infrastructure virtual storage server is on node 2.

storage layoutI recommend to use NetApp SPM tool to figure out the storage data layout.  NetApp partners or sales engineers should all have access to this tool.

For hosted shared desktops and hosted VDI, storage best practice is similar.

PVS vDisk  CIFS/SMB 3 is used to host the PVS vDisk. CIFS/SMB 3 allows the same vDisk to be shared among multiple PVS servers and still has resilience during the storage node failover. This results in significant operational savings and architecture simplicity.

PVS write cache file. The PVS write cache file is hosted on NFS datastores for simplicity and scalability.  Deduplication should not be enabled on this volume.

Profile Management. To make sure that the user profiles and settings are preserved. We leverage the profile management software Citrix UPM to redirect the user profiles to the CIFS home directories.

User Data Management NetApp recommends hosting the user data on CIFS home directories to preserve data upon VM reboot or redeploy.

Monitoring and management NetApp recommends using OnCommand Balance and Citrix Desktop Director to provide end-to-end monitoring and management of the solution.


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Join me for FlexPod Datacenter with Citrix XenDesktop Validated Design webex

FlexPod Datacenter with Citrix XenDesktop Validated Design

Converged solutions, which combine desktop operating systems, applications, compute, network and storage improve agility, simplify the deployment and reduce the cost of desktop virtualization.

In this webinar, you will discover how the validated design of FlexPod Datacenter with Citrix XenDesktop works to remove the bottlenecks to desktop virtualization and reduce infrastructure, operations and deployment costs.

Join us and you will learn how to:

  • Optimize large, enterprise-grade desktop virtualization deployments
  • Implement Cisco Validated Designs (CVDs) to design a reliable and predictable storage infrastructure
  • Validate performance for a cost-effective, flexible and scalable reference architecture

This event will also take place at 10 am PT/ 1 pm ET. To register for the 2nd session, please click here.


Screen Shot 2014-03-03 at 11.08.06 PM

Posted in flexpod, NetApp Clustered ONTAP, Storage Discussion, virtual desktop | Tagged , , , , , , , , | Leave a comment