High-Performance Persistent Virtual Desktop Architecture Powered by NetApp FAS Array and Atlantis ILIO

Reference Architecture | January 2014

NetApp: Chris Rodriguez, Nick Triantos, Troy Magnum, Abhinav Joshi

Atlantis Computing: Bharath Nagaraj, David Leathers, Seth Knox

High-Performance Persistent Virtual

Desktop Architecture Powered by

NetApp FAS Array and Atlantis ILIO

Contents

Introduction and Scope ... 2

NetApp and Atlantis Computing Architecture Highlights ... 2

Architecture ... 3

Atlantis ILIO Storage Optimization Overview ... 4

Content-Aware IO Optimization ... 4

In-line Deduplication ... 4

Wire-Speed Compression ... 5

Real-Time Write Coalescing ... 5

High Availability and Disaster Recovery ... 5

Automated VDI Deployments with Atlantis ILIO ... 5

NetApp FAS2200 Series Overview ... 6

Clustered Data ONTAP Overview ... 6

Performance and Validation Testing ... 10

Performance Test Tools and Test Plan ... 12

Login VSI 3.7 ... 13

Iometer ... 13

Atlantis Computing Workbench ... 14

PassMark Performance Test 8.0 ... 14

Test Results ... 15

Login VSI 3.7 Heavy ... 16

NetApp FAS 2240-2 Storage Array Scalability ... 18

Iometer ... 20

PassMark Performance Test 8.0 (Disk Mark) ... 20

Configuration Best Practice ... 21

Atlantis ILIO Configuration Best Practice ... 21

NetApp FAS Best Practices ... 22

Storage Sizing Guidance ... 25

Summary ... 26

Introduction and Scope

Virtual Desktop Infrastructure (VDI) is one of the fastest growing markets in the IT industry. IT

departments are under pressure to virtualize more and more of their users’ desktops to take advantage of centralized management, mobility, and security benefits offered by VDI. With the success of initial VDI projects and the diversity of the desktop user community, comes a requirement for virtual desktop performance with more IOPS than physical PCs. IT departments must provide virtualized desktops that can support over 50 IOPS per desktop without any negative impact to the end-user experience, and without overpaying for the VDI infrastructure.

High-performance virtual desktops make it challenging for the infrastructure to provide a greater level of storage performance. To meet these challenges, NetApp® and Atlantis Computing® have partnered to provide a storage architecture to meet the VDI IOPS requirements. The NetApp and Atlantis ILIO® architecture enables IT departments to meet the requirement by providing more than 55 IOPS per desktop and 30GB per virtual desktop for 1,000 persistent virtual desktops using a dual controller NetApp FAS 2240-2 with Clustered Data ONTAP optimized with Atlantis ILIO software.

NetApp and Atlantis Computing Architecture Highlights

 Simplicity

o Simple storage architecture, easy to deploy and manage o Automated deployment and configuration

 User Experience

o Better-than-PC user experience

o Efficiently meets all data mobility storage needs  Economics

o CAPEX: Lower total cost than a physical PC

o OPEX: Reduce power, cooling and datacenter footprint  Complete VDI Architecture

o Proven architecture that scales beyond 10,000 users o Enables high availability and disaster recovery

Architecture

The NetApp FAS and Atlantis ILIO Persistent VDI architecture includes the following components: VDI Broker – Customers may choose their preferred VDI broker including Citrix XenDesktop and VMware Horizon View to connect users to their persistent virtual desktop from any device. Hypervisor – Customers may choose their preferred hypervisor to enable a hypervisor host to run persistent virtual desktops. The architecture supports various hypervisors. Validation testing of the architecture was conducted on VMware vSphere 5.1.

Hypervisor Host – Customers may choose their preferred hypervisor host to run the persistent virtual desktops. The validation test was conducted using servers with Intel Xeon e5-2687 with 16 cores @ 3.10 GHz and 256GB RAM.

Host-Based Virtual Desktop Optimization – Atlantis ILIO provides application analysis, IO processing, inline deduplication and compression of persistent virtual desktops at the host level to terminate unnecessary IO operations before reaching the storage system, increasing storage scalability and reducing network traffic.

Storage – The NetApp FAS array acts as the primary storage for all of the persistent virtual desktops and provides the IO performance and throughput necessary to support 1,000 persistent virtual desktop

Atlantis ILIO Storage Optimization Overview

Atlantis ILIO is a VDI storage and performance optimization software architecture that works with the NetApp FAS Array to optimize storage utilization, boost desktop performance, and enable large, highly scalable VDI deployments. Atlantis ILIO is a unique and innovative storage optimization technology that fundamentally changes the economics and performance characteristics of VDI by intelligently optimizing how virtual machines interact with storage systems.

Atlantis ILIO In-Memory Storage™ technology is a 100% software host-based IO optimization

technology that handles read and write IO at memory speeds. Through a combination of patent-pending technologies, Atlantis ILIO helps reduce the IO and storage capacity requirements for VDI deployments of any scale. The NetApp FAS 2240-2 Array with Atlantis ILIO delivers a cost-efficient storage

architecture for persistent virtual desktops that would normally consume 30-80GB using as little at 3GB of storage per desktop.

Atlantis ILIO deploys as a dedicated VM on each host, presenting a conventional NFS datastore used by all the VMs on that host. Atlantis ILIO deployment is transparent and does not affect administrative processes and procedures that may already be in place. During runtime, all IO from the VMs is first processed by the Atlantis ILIO VM, and then written to the NetApp FAS 2240-2 Array. As IO enters the Atlantis ILIO VM, it is first analyzed, then it is deduplicated, compressed and then undergoes write coalescing. Then, the IO is sent to the NetApp FAS 2240-2 Array which first does write IO coalescing in NVRAM before writing data to disks. This end-to-end Atlantis ILIO and NetApp FAS IO operation occurs at wire speeds without impacting the Atlantis ILIO ability to service IO at server RAM speeds. The Atlantis ILIO storage optimization technologies used include content-aware IO optimization, in-line deduplication, wire-speed compression, and real-time write coalescing.

Content-Aware IO Optimization

Atlantis ILIO’s content-aware IO optimization focuses on the minimization of IO operations. In Windows NTFS (and other file system environments), a lot of the IO generated is transient. Atlantis ILIO uses its intelligence to differentiate between transient and stateful operations that require shared storage. When IO enters the Atlantis ILIO VM and is processed, transient IO is processed at the hypervisor host layer itself, while stateful IO is deduplicated, compressed and coalesced before being sent to the NetApp FAS 2240-2 Array. This reduces the amount of IO going to shared storage, thereby helping reduce storage cost per desktop. Data integrity is maintained throughout this process.

In-line Deduplication

With virtual desktop infrastructure, most VMs have a significant amount of redundant data. Atlantis ILIO efficiently identifies redundancies and deduplicates data at the block level in-line in real time on the host. As a result, the NetApp FAS 2240-2 Array is able to support 1,000 persistent virtual desktops that are 30GB in size and 55 IOPS using only 3-8TB of storage.

Wire-Speed Compression

Atlantis ILIO technology includes lossless compression, which can be applied to the deduplicated IO stream before it is written to primary storage. Atlantis ILIO uses an enhanced, patent-pending

implementation that performs the compression out of band, imposing no IO latency impact of any kind. Atlantis ILIO performs all compression in real time at wire speeds to provide space-saving benefits, while at the same time significantly improving overall desktop performance relative to physical PCs. When operating together, the in-line deduplication and wire-speed compression can help reduce the size of a persistent virtual desktop by up to 95%.

Real-Time Write Coalescing

With real-time write coalescing, small block random writes that are so common in virtual desktop IO are re-ordered into a much more sequential stream of large block writes. In concept, this is very similar to the IO optimizations that the Windows desktop OS performs, but the difference is that Atlantis ILIO performs it at the level of the entire host, not individual desktop images.

High Availability and Disaster Recovery

Atlantis ILIO Persistent VDITM seamlessly integrates with the High Availability (HA) capabilities of the virtual desktop hypervisor to provide fully automated recovery of all affected desktops when a server or rack fails. In addition, Atlantis ILIO enables highly efficient Disaster Recovery (DR) for all your virtual desktops across data centers as it minimizes the amount of data that needs to be replicated.

Automated VDI Deployments with Atlantis ILIO

Atlantis ILIO provides push-button, fully automated deployment, configuration, sizing, and datastore creation for thousands of persistent virtual desktops across multiple racks of servers. Atlantis ILIO virtual machines are automatically created and registered as NFS data stores that are ready to use by Citrix XenDesktop or VMware Horizon View to complete the desktop provisioning process.

NetApp FAS2200 Series Overview

NetApp FAS2200 offers powerful, affordable, flexible data storage for midsized businesses and distributed enterprises. Midsized businesses and enterprises with distributed environments need powerful, flexible data storage to handle data growth. The NetApp® FAS2200 series, named a “Champion” and “Best in Overall Value” by Info-Tech Research Group, is affordable, and is a more powerful storage platform than other systems in its class.

 Start right with unified storage for SAN and NAS. Accelerate application performance and optimize storage costs with NetApp Flash Accel™ Server Cache and Flash Pool™ Intelligent Caching.

 Keep it simple with intuitive storage management tools that integrate with key business applications and virtualization environments.

 Grow smart while protecting your storage investment, with cluster-ready upgrades using the same NetApp operating system and software tools.

NetApp software on FAS2200 systems reduces disk purchases by 50% or more and cuts provisioning time by up to 90%.

The NetApp FAS2200 series delivers no-compromise unified storage, with industry-leading efficiency features at no additional cost, to boost performance and handle storage growth. For more details and tech specs on the FAS2200 series platform visit: http://www.netapp.com/us/products/storage-systems/fas2200/index.aspx.

For details on higher end FAS 3200 and FAS 6200 storage arrays, please visit: http://www.netapp.com/us/products/storage-systems/

Clustered Data ONTAP Overview

Scaling performance while controlling costs is one of the most challenging efforts in the datacenter. High-performance, technical computing, and digital media content applications place extreme demands on storage systems. Compute clusters running these applications can require multiple gigabytes per second of performance and many terabytes—or even petabytes—of capacity. To maintain peak application performance, users must be able to add storage and move data between systems and tiers of storage without disrupting ongoing operations. At the same time, to control costs, users must be able to effectively manage the storage environment.

Clustered Data ONTAP addresses these challenges and provides high-performance and high-capacity requirements. It enables organizations to address faster time to market by providing massive throughput and the scalability necessary to meet the demanding requirements of high-performance computing and virtualization infrastructures. These high-performance levels address the growing demands of performance, manageability, and reliability for large Linux®, UNIX®, Microsoft®, or VMware clusters.

Clustered Data ONTAP is an operating system from NetApp that includes:

 Nondisruptive operations based on a clustered file system hosted on interconnected nodes.  Multinode scaling with global namespacing technologies.

 NetApp FlexVol® for storage virtualization.

 NetApp backup and recovery solutions based on local Snapshot™ copies, replication, and mirroring.

Clustered Data ONTAP Benefits

NetApp’s storage clustering feature within Data ONTAP provides a number of key benefits, including the ability to:

 Accelerate performance. Clustered Data ONTAP uses a clustered file system technology to provide maximum input/output (IO) throughput and remove the bottlenecks that affect production. Information can be striped as volumes across any or all of the storage controllers and disks in the system, which enables balanced levels of throughput for even a single file or volume and allows technical teams to run multiple compute jobs concurrently. When many compute nodes simultaneously require data, you can use load-balancing mirrors within Data ONTAP with a clustering system or add NetApp FlexCache® storage accelerators in front of the system to deliver much higher read throughput.

 Simplify storage and data management. Clustered Data ONTAP supports fully integrated storage solutions that are easy to install, manage, and maintain. Enhancing this with its global namespace capability, administrators can simplify client-side management by mapping all data volumes in the cluster into a file system tree structure that automatically maps or remaps servers to their data, even if that data is moved. By offering a single system image across multiple storage nodes, the global namespace eliminates the need for complex automounter maps and symbolic link scripts.

 Improve data access. Storage is virtualized at the file system level to enable all compute nodes to mount a single file system, access all stored data, and automatically accommodate physical storage changes that are fully transparent to the compute cluster. Each client can access a huge pool of information residing anywhere in the storage cluster through a single mount point.

 Keep resources in balance without disrupting operations. As storage nodes are added to the cluster, physical resources, including CPU, cache memory, network IO bandwidth, and disk IO bandwidth, are kept in balance automatically. Clustered Data ONTAP enables you to add storage and move data between storage controllers and tiers of storage without disrupting users and applications. This ushers in a whole new paradigm in which capacity increases, workload balancing, eliminating storage IO hot spots, and component deprecation become normal parts of the datacenter without needing to schedule downtime. More importantly, these tasks are accomplished without the need to remount shares, modify client settings, or stop active workloads as is typically the case with traditional or other high-performance computing storage systems.

 Simplify installation and maintenance. Using standard Network File System (NFS) and Common Internet File System (CIFS) protocol to access clustered Data ONTAP systems without needing to install special clients, network stack filters, or code on each server in the compute cluster is the value of a unified storage product. The clustered Data ONTAP architecture also reduces or eliminates routine capacity allocation and storage management tasks, resulting in more time to address organizational goals and objectives and less time spent managing storage.

 Meet high-availability requirements. Along with stringent performance requirements, high reliability is important for technical applications and cluster computing. Clustered Data ONTAP leverages core NetApp software such as WAFL® (Write Anywhere File Layout), RAID-DP®, and NetApp Snapshot. RAID-DP, a high-performance implementation of RAID 6, protects against double-disk failures, and transparent node failover automatically bypasses any failed components with no interruption in data availability. In addition to having no single point of failure, clustered Data ONTAP supports the expansion or reconfiguration of the storage

infrastructure while online, enabling applications to run uninterrupted as more storage capacity, processing power, and/or throughput is added.

 Enable continuous operations. Clustered Data ONTAP is configured for continuous operation with the use of high-performance and modular NetApp storage components. Each system consists of one or more fabric-attached storage (FAS) building blocks, and each FAS building block is a high-availability pair of controllers (storage nodes). Multiple controller pairs form a single, integrated cluster. Clustered Data ONTAP uses Ethernet technology—Gigabit (Gb) and 10Gb—for server connections and for interconnecting FAS controllers. Servers can also be connected through InfiniBand using a gateway device. Each controller can support any mix of high-performance SAS and cost-effective SATA disk drives. Data can move nondisruptively between nodes or between different tiers of disk as performance requirements change. This capability makes sure that datacenter and IT administrators can maximize performance where needed while simultaneously improving capacity utilization.

Clustered Data ONTAP Concepts

Regardless of size and complexity, datacenters and IT organizations look for cost-effective

approaches to solve challenges and address requirements. Infrastructure optimization has been

part of the storage industry since it began, with vendors driving technologies such as thin

provisioning, deduplication, storage tiering, and so on. Certainly the broad acceptance and

rapid adoption of virtualization are prime examples of how quickly technology is put into place

to promote a growing cliché: do more with less. Whether it is storage, virtualization, or

something completely different, any new technology brings with it concepts and terms meant

to bind concrete associations to support abstract ideas. With NetApp clustered Data ONTAP, it

is no different. This section introduces new terms and concepts to establish a knowledge

baseline for the remainder of this document.

What Makes Up a NetApp Storage Cluster?

Although normally reserved for a glossary, it is important to address some key terms early in the text to establish a common knowledge baseline.

 Cluster. The information boundary and domain within which information moves. The cluster is where high availability is defined between physical nodes and where Vservers operate.

 Node. A physical entity running Data ONTAP. This physical entity can be a traditional NetApp FAS controller; a supported third-party array front ended by a V-Series controller; and NetApp’s virtual storage appliance (VSA), Data ONTAP-v™.

 Vserver. A secure virtualized storage controller that behaves and appears to the end user to be a physical entity (similar to a VM). It is connected to one or more nodes through internal networking relationships (covered later in this document). It is the highest visible element to an external consumer, abstracting the layer of interaction from the physical nodes. Based on these two statements, it is the entity used to provision cluster resources and can be

Performance and Validation Testing

NetApp and Atlantis Computing jointly designed a test plan to validate the performance, scalability and reliability of the joint architecture using a combination of industry standard benchmarking tools such as Login VSI, PassMark and Iometer combined with the Atlantis Computing Workbench load generation tool. The environment was tested with 1,000 concurrent persistent virtual desktops using eight servers running 125 virtual desktops and one Atlantis ILIO virtual machine per server. In addition, the Atlantis Computing Workbench load generator was also used in combination with Login VSI to simulate the desktop load of 1,000 persistent virtual desktops with 55 IOPS per desktop.

To test this configuration, we created a 1,000 user persistent VDI environment and ran the performance tests against a dual controller configuration on the NetApp FAS 2240-2 array. The goal of the test was to demonstrate a resilient enterprise ready architecture that can support 1,000 high-performance virtual desktops delivering 55+ IOPS and 30 GB of capacity per VDI user with only twenty four 600GB 10K RPM internal SAS drives (8.1TB Usable) in the 2U NetApp FAS 2240-2 Array.

The environment was tested with the following configuration:

 1,000 concurrent persistent virtual desktops each generating 55 IOPS per desktop  Eight physical servers running VMware 5.1 and hosting 125 virtual desktops per server  One Atlantis ILIO virtual machine per physical server

Table 1) Test Environment Configuration

Specifications and Configurations Virtual

Desktop Configuration

 1,000 full clone persistent virtual desktops (full clones) at 55 IOPS per desktop to simulate 1,000 users at 55 IOPS per desktop

 Atlantis ILIO Fast Clones used to create full clones for each desktop  1vCPU

 1.5GB of RAM reserved per desktop  1 VMXNET3 network adapter

Servers  8 servers

 125 virtual desktops per server

 CPU – 16 CPU cores (2 x 8) @ 3.099 GHz  256GB RAM

 Hyper threading active

Networking  Cisco Nexus 2048 10 GbE switch

 2x 10 GbE links to NetApp 2240-2 (one to each controller)  1 x 10 GbE links to each host server

Storage  NetApp FAS 2240-2 Array

 Dual controllers with active/standby configuration  24 x 600GB 10K RPM internal SAS drives (8 TB used)

 Active Controller: 17+2 RAID DP Aggregate (Data + Root); 1 Spare  Standby Controller: 1+2 RAID DP Aggregate (Root); 1 Spare  8 1TB NFS Volumes with 1 NFS Volume mapped to each ESX host  8.1TB of usable capacity

Atlantis ILIO Virtual Machine

 CPU – 1 vCPU reserved and 1 vCPU allocated (total of 2 vCPUs allocated)

 RAM – 45GB (standard sizing only requires 24GB – see Atlantis Computing Administrators Guide and Sizing Tool for more details)  1 Atlantis ILIO virtual machine per server (8 servers total)

 125 VM’s per Atlantis ILIO datastore

 Each Atlantis ILIO datastore was allocated 1 TB from a NetApp FAS 2240-2 NFS VOLUME. The total allocated capacity for 1,000 users was 8TB.

Performance Test Tools and Test Plan

The validation of the NetApp FAS Array with Atlantis ILIO Persistent VDI architecture included performance and scalability testing for 1,000 “heavy” persistent virtual desktops at 55 IOPS per desktop using a combination of Login VSI, PassMark Performance Test and the Atlantis Computing Workbench tool. The testing focused on measuring storage performance with a single controller of the dual controller configuration under extremely heavy load.

Table 1. Test Case Overview

Workload Test Cases

Scale Testing and

IOPS Offload Login VSI 3.7 Heavy workload was used to generate load for 1,000 persistent _{virtual desktops generating 10-15 IOPS per desktop. Simultaneously, the Atlantis} Computing Workbench generated additional IOPS to simulate a much heavier user load. The amount of IOPS generated by the Atlantis Computing workbench tools was increased in 5 IOPS per desktop increments until the Login VSI Heavy workload test failed due to increased response times. Login VSI, VSImax was not reached at 55 IOPS per desktop; however, the Login VSI max was reached when running the test at 60 IOPS per user.

Therefore, the maximum sustained IOPS per desktop supported by the joint architecture is 55 IOPS per desktop during this test for 1,000 users for a total of 55,000 IOPS to test 1,000 users at 55 IOPS per desktop.

During this test, the IOPS offload was measured to show the difference between the number of IOPS serviced by the Atlantis ILIO VMs compared to the amount of IOPS required from the NetApp FAS array. This offload percentage can be used to extrapolate IOPS sizing for different configurations of NetApp FAS storage arrays such as the FAS 3200 and 6200 series hybrid arrays for larger deployments.

In addition, the NetApp FAS storage controller utilization and disk utilization were measured during the test.

Comparing VDI to Physical PC Disk Performance

PassMark Performance Test 8.0 Disk Mark was used to compare the disk performance of a virtual desktop running on the NetApp FAS storage array with Atlantis ILIO compared to a physical PC with a dedicated SATA drive and a MacBook Air with an Apple SSD.

Iometer Iometer was used to show the maximum IOPS available from the NetApp FAS array with Atlantis ILIO.

Login VSI 3.7

Login Virtual Session Indexer (Login VSI) is the de-facto industry standard benchmarking tool to test the performance and scalability of centralized Windows desktop environments like Server Based

Computing (SBC) and Virtual Desktop Infrastructures (VDI). Login VSI is 100% vendor independent and is used to test virtual desktop environments like Citrix XenDesktop and XenApp, Microsoft VDI and Remote Desktop Services, VMware Horizon View or any other Windows based SBC or VDI architecture. Login VSI is used for testing and benchmarking by all major hardware and software vendors, and is recommended by both leading IT-analysts and the technical community. Login VSI is vendor independent and works with standardized user workloads, therefore conclusions that are based on Login VSI test data are objective, verifiable and replicable. Throughput of the test consists of a

pass/fail rating as well as the overall response time which cannot rise the baseline performance * 1.25 + 3000ms.

Login VSI is also the standard tool used in all tests that are executed in the internationally acclaimed Project Virtual Reality Check (www.projectvrc.com).

To validate that the joint NetApp and Atlantis ILIO architecture can deliver the ultimate user

experience under the heaviest IOPS load, the architecture was tested using Login VSI Heavy workload, while at the same time generating approximately 5 times more IOPS (55 total IOPS per user) using the Atlantis Computing Workbench (see next section).

For more information about Login VSI, or a free test license, visit www.loginvsi.com

Iometer

Iometer is an IO subsystem measurement and characterization tool for dual controller and clustered systems. It is used as a benchmark and troubleshooting tool and is easily configured to replicate the behavior of applications. In this test, Iometer was configured to simulate a VDI workload and determine the maximum available IOPS of the joint Atlantis ILIO and NetApp FAS array. The VDI workload tested was configured to be 80% write, 20% read and 80% random with a 4K block size using an 800GB test file. A virtual machine with Iometer was run with this test profile simultaneously on 8 servers to determine the maximum available IOPS for the NetApp FAS Storage Array with Atlantis ILIO Software.

To download the configuration file and reproduce the test, click here https://atlantiscomputing.sharefile.com/d/s4038670e9454e15b

For more information on how to use Iometer to test desktop workload, visit:

Atlantis Computing Workbench

The Atlantis Computing Workbench is a load generation tool that was used to add additional IOPS load with a specific configuration that simulates heavy persistent virtual desktop workloads with unique data. It allows a complete IO simulation of a VDI workload by configuring the IO access patterns with specific block sizes, frequency of change, threads, and unique data versus duplicate data. The workbench was run concurrently with the Login VSI Heavy workload test run and configured to generate 2-4GB of unique data per user (2-4TB Total) during the 2 hour Login VSI run with 65% unique blocks and 35% duplicate blocks.

PassMark Performance Test 8.0

Performance Test is a benchmarking tool designed to measure the performance of physical PCs. Using the test, we are able to compare a virtual desktop disk performance with hard drives of different types of physical PCs that have been previously benchmarked by individuals and uploaded to the PassMark database. The Performance Test Disk Mark test measures the data transfer speed when reading or writing data to one or more disks. For comparison purposes, we selected a PC with a Western Digital 7,200 RPM SATA drive and a MacBook Air with an Apple SSD.

Test Results

Test Results

Login VSI 3.7 Heavy workload with Atlantis Computing Workbench

 Login VSImax Not Reached for 1,000 user test at 55 IOPS per desktop  Login VSI baseline of 1352 ms

 VSI Index Average consistently below 2500 ms at full scale

 Average utilization of the NetApp FAS2240-2 active controller was 68%

PassMark

Performance Test 8.0 Disk Mark

 Disk Mark score of 3841 Performance is comparable to having an enterprise-class SSD drive for every virtual desktop

 3 times better disk mark score than a MacBook Air with an Apple SSD  6 times better disk mark score than a PC with a 7200 RPM SATA drive Iometer  Total available IOPS of 167,472 for the NetApp FAS 2240-2 with 24 x

600GB 10K RPM SAS drives and Atlantis ILIO

Storage Scalability  The joint NetApp FAS 2240-2 Array with Atlantis ILIO optimization was able to deliver scalability of 1,000 users (at 55 IOPS per desktop) per NetApp FAS 2240-2 array with 24 x 10K SAS

 The joint architecture can scale in pods of 1,000 users at 55 IOPS per desktop (1 NetApp FAS 2240-2, 8 servers with Atlantis ILIO software) to an unlimited number of desktops

 The storage system has enough head-room to survive a single controller failure with no impact to the user experience

Login VSI 3.7 Heavy Workload

For this test, the Login VSI 3.7 Heavy workload was used to maximize the load generated on the storage system. The Login VSI Heavy workload test generated 10-15 IOPS per desktop (15,000 IOPS Total). While Login VSI was running, the Atlantis Computing Workbench tool was used to generate an additional 40 IOPS per user (40,000 IOPS total) with 65% unique data to simulate an extremely heavy storage load on the system. This means that the system was handling approximately 55 IOPS (5 times more load than Login VSI Heavy workload alone) with an excellent user experience.

On the VSImax chart, the y-axis is the response time in milliseconds that Login VSI 3.7 recorded while executing testing operations on the virtual desktop sessions and the x-axis is the number of virtual desktops tested. The VSImax calculation is based on the response times of seven operations that run continuously in 12-14 minute loops for the duration of the test. The operations are intended to simulate a power user’s application activities on a virtual desktop. The seven operations are: Starting Notepad, Starting the File Open dialogue, starting the Print dialogue, copying a file from, archive a document with 7-zip, starting “search and replace” dialogue and starting Microsoft Word with a document. These operations utilize different resources such as virtual desktop CPU (user and kernel), memory, and disk. If such operations continually require a high number of seconds to complete, the user will regard the performance of the virtual desktop as being slow. Therefore, Login VSI considers a response time that is 1.25 times the baseline response time (when there is no stress on the system) + 3000 ms as

unacceptable. A Response time of 3000 milliseconds to 4000 milliseconds is considered good, 2000 to 3000 as very good, and 1,100 to 2000 as excellent. A Key highlight for this joint architecture is that the response time is within 1300 to 2500 range, which is very good to excellent with very little increase in response time as additional users are added to the running the workload.

R es p o n se T ime ( m s) Number of Users

In this test, the baseline of the system was 1352ms response time, which is 3 times faster than the acceptable user experience. As the load increased to 1,100 users, the Login VSI Index Average remained consistently in the 2000-2500ms range with no degradation of user experience as the system scaled. As a result, the Login VSImax was not reached, indicating that the system could scale to the 1,100 users tested, even with the additional 40 IOPS generated by the Atlantis Computing Workbench.

In this test, the baseline of the system was 1352ms response time, which is 3 times faster than the acceptable user experience. As the load increased to 1,000 users, the Login VSI Index Average remained consistently in the 2000-2500ms range with no degradation of user experience as the system scaled. As a result, the Login VSImax was not reached, indicating that the system could scale to the 1,000 users tested, even with the additional 40 IOPS generated by the Atlantis Computing Workbench.

IOPS Offload During the 1000 user LoginVSI Test with 55 IOPS per user Load

During our LoginVSI and Atlantis workbench test, we measured the number of IOPs directly serviced by the Atlantis ILIO VMs (blue), the number of IOPs serviced by the NetApp FAS array (red), as well as, provide a 10 second moving average, depicting sustained IOP levels (yellow). On average, the IOPS Offload percentage was 79% with a peak of 87%. IO Offload is a key metric in that it provides higher VM storage density, and significantly reduces network and storage traffic.

NetApp FAS 2240-2 Storage Array Scalability

In order to determine the number of users that can be supported by the joint NetApp FAS 2240-2 and Atlantis ILIO architecture, it was important to measure controller utilization, disk utilization and the storage capacity consumed during the 1,000 user Login VSI with Atlantis ILIO workbench 55 IOPS test. Controller Utilization

During the LoginVSI Heavy workload and Atlantis Computing Workbench load test, the NetApp FAS 2240-2 controller CPU utilization was measured to ensure that the system was able to handle the load on the active controller of the dual controller storage array for an extended period of time. The chart below shows that the controller utilization remains within acceptable limits throughout the test. All desktops were running from one of the two available controllers on the NetApp FAS 2240-2, providing a standby controller that would be able to pick up the entire load in the event of the active controller failure. At the end of the test, the desktops completed the workload and started to idle, explaining the decrease in controller utilization in the final minutes of the chart.

The results of the test showed that the 60 second moving average for the NetApp FAS 2240-2 controller utilization remained within the acceptable limits. The overall average controller utilization was 68% as shown in the chart above.

Desktop workload completed lowering controller utilization

Disk Utilization

During the Login VSI Heavy workload and Atlantis Computing workbench load test, the NetApp FAS 2240-2 disk utilization was measured to ensure that the system was able to handle the load within acceptable disk utilization limits for an extended period of time.

The result of the test showed that the 60 second moving average for the NetApp FAS 2240-2 disk utilization remained within acceptable disk utilization threshold. The blue lines represent disk utilization for every second across the entire test run, while the black line shows a 60 second moving average of the same data points. The overall average disk utilization averaged 30%, with a 60 second moving average approaching 60% disc utilization and peaks up to 100% for a period of 7 total seconds. Disk Latency

The average write latency on the NetApp 2240-2 volumes was approximately 1 ms (max latency = 1.2 ms, average latency = 0.85 ms) and the reads averaged less than 10 ms. In this test, the write latency on the NetApp is the critical measurement as most reads are serviced by the Atlantis ILIO datastore on each server from local server memory with microsecond (less than 1 ms) latency.

all 1,000 persistent virtual desktops with 50GB of provisioned storage space and 30GB used data in the VMDKs were provisioned onto the 8 servers and 2 weeks of continuous Login VSI and PassMark testing runs, the datastores had 98% headroom still available for virtual desktop growth.

Iometer

Iometer was used to determine the maximum number of IOPS available from the NetApp FAS 2240-2 Storage array with Atlantis ILIO optimization. Iometer was installed on a Windows 7 virtual desktop on each of the 8 servers and run simultaneously. When optimized with Atlantis ILIO, each server ranged between 17,727 and 19,686 IOPS with an average of 18,608 IOPS per server. The total IOPS available across the 8 servers was 167,472. The 167,472 IOPS was achieved using the Atlantis ILIO software in combination with a dual controller NetApp FAS 2240-2 array with 24 10K SAS drives that is intended to support up to 1,000 users. When scaling beyond 1,000 users, it is recommended that customers deploy multiple pods (a pod being 8 servers with Atlantis ILIO and 1 NetApp FAS 2240-2 storage array). As customers add additional pods, the total number of IOPS will increase linearly (2 pods will provide up to 334,944 IOPS, 5 pods will provide up to 837,360 IOPS).

PassMark Performance Test 8.0 (Disk Mark)

The PassMark Performance Test 8.0 Disk Mark is a tool designed to measure physical PC disk performance. The tool generates a disk workload that simulates a physical PC with random and sequential reads and writes, and then assigns a score based on an index of the results that represents the overall disk performance of the PC. The tool enables individuals who run the test to upload their

results to an online database of test results that can be used as baselines to compare PC disk performance.

In this test, the NetApp FAS 2240-2 with Atlantis ILIO optimization had a Disk Mark score of 3,841. In comparison, a physical PC with a 7200 RPM Western Digital hard drive scored 563 while a MacBook Air with an Apple SSD scored 1191. This test showed that a persistent virtual desktop with NetApp and Atlantis ILIO storage provides more than six times faster disk performance than a traditional physical PC and more than three times better disk performance than a MacBook Air with an SSD.

Configuration Best Practice

Atlantis ILIO Configuration Best Practice

When using Atlantis ILIO for persistent VDI, it is recommended that customers use VMware DRS and Affinity rules to control the placement of virtual machines on hosts within a DRS cluster. There are two types of Affinity rules:

1. Rules used to specify affinity or anti-affinity between a group of virtual machines and a group of hosts. An affinity rule specifies that the members of a selected virtual machine DRS group can or must run on the members of a specific host DRS group. An anti-affinity rule specifies that the members of a selected virtual machine DRS group cannot run on the members of another specific host DRS group. When using Atlantis ILIO, set affinity between the Atlantis ILIO virtual machine and the persistent virtual desktop VMs that are associated with it to ensure that they are always on the same host. This will ensure the best possible performance and avoid any additional network traffic.

2. Rules used to specify affinity or anti-affinity between individual virtual machines. A rule

specifying affinity causes DRS to try to keep the specified virtual machines together on the same host, for example, for performance reasons. With an anti-affinity rule, DRS tries to keep the specified virtual machines apart, for example, so that when a problem occurs with one host, you do not lose both virtual machines. Anti-affinity rules are not used in ILIO deployment scenarios as they might interfere with HA.

Networking Adapters

Always configure the Atlantis ILIO virtual machine with VMXNet3 adapters (10 Gb Ethernet adapters), even when deployed on a 1GbE network, so that desktop VMs can perform IO at maximum bus speeds

provides the lowest CPU utilization and best IO performance for the virtual hard disk performance of a virtual desktop VM.

Microsoft Windows XP Alignment

Microsoft Windows XP virtual desktops should always be configured with paravirtualized SCSI drivers. Microsoft Windows Client OS versions released prior to Microsoft Windows Vista (Windows XP and earlier) do not align the OS partition to the block boundary of the underlying disk, causing performance degradation and sub-optimal storage consumption on a deduplicated file system. This is a well-known limitation of the Windows XP OS. It is strongly recommended that the Microsoft Windows XP VM be aligned using a tool such as VMware Converter before being migrated or installed on the Atlantis ILIO datastore.

NetApp FAS Best Practices

 Use 16 to 20 drives for raid-group size in an aggregate  Upgrade to the latest Clustered Data ONTAP (cDOT)  Create a load sharing mirror of the VServer root volume  Create Logical Interface Failover groups

 Segregate NFS and CIFS traffic on their own vlan  Set the NFS vlan non-routable

 Use 10GbE adapters for data network (NFS)  Set flow control to none on 10GbE adapters

 Create multiple volumes for the VDI delta/write-cache/difference disks to take advantage of multi-threading of the storage processors

 Group Master / Golden templates and turn on storage dedup on those volumes

 Do not turn on dedup for snapshot volumes (link clones, MCS, etc.), write-cache disks and swap space.

 For non-persistent virtual desktops (stateless, pooled), Thin provision at the storage layer the write-cache / disposable / differential disks.

Networking Switches:

 Turn off flow controller on 10GbE network

 Turn off Spanning tree on switches (enable port fast or set as an edge)

 Use a Virtual Port Channel (VPC) across two swtiches with LACP if VPC is available on switch. If not, use LACP lag to each switch with dual switches for redundancy

High Availability of Persistent Virtual Desktops with Atlantis ILIO in a

VMware vSphere

Environment

VMware High Availability (HA) is a component of VMware vSphere™ that provides rapid recovery from outages by using a vSphere HA cluster of hosts. When a failure is detected in the HA cluster, the virtual machines on the failing host are restarted on other hosts within the cluster.

When deploying a persistent virtual desktop, organizations have the option of deploying Atlantis ILIO virtual machines in a VMware High Availability (HA) configuration to minimize downtime caused by hardware failures. VMware HA enables Atlantis ILIO to provide rapid recovery from hardware failures by restarting virtual machines on a standby host in the same HA cluster. VMware HA maintains a heartbeat between hosts in the cluster so a failure can be detected and recovery started as quickly as possible. VMware HA is configured with affinity rules to specify the fail-over host and startup sequence so that the virtual desktops are recovered onto the same standby host with the same Atlantis ILIO datastore. The benefits of using Atlantis ILIO with VMware HA are:

 Proven VMware HA clustering technology.  No increase in storage footprint.

 Minimal downtime after a failure.

The diagram above shows a VMware HA configuration for an Atlantis ILIO configuration with two active hosts and one standby host. The active hosts contain running Atlantis ILIOs and virtual desktop VMs. The standby host does not initially have any virtual machines running on it. However, if one of the active hosts fails, VMware vSphere restarts on the standby host the virtual machines that were executing on the failed host. All backend storage devices and all Atlantis ILIO storage devices are mounted on the standby host to facilitate restarting VMs on the standby host.

For more information, see the Atlantis ILIO VMware High Availability Setup Guide available on the Atlantis Computing Customer Portal.

Storage Sizing Guidance

Based on the IOPS, capacity requirements per desktop, and storage system utilization discussed in the Test Results section, the Atlantis ILIO and NetApp FAS array storage scalability guidelines are listed below.

For deployments with more than 1,000 users, the following options are available to customers:  Scale-Out Pod-Based Architecture – Deploy multiple NetApp FAS 2240-2 storage arrays in

pods up to 1,000 users (at 55 IOPS per desktop)

 Scale-Up using NetApp FAS 3000 or 6000 series – Deploy higher end NetApp FAS 3200 or 6200 series storage arrays with additional disk shelves.

1. Scale-out Pod-Based Architecture

With the scale-out approach, customers create 1,000 user Pods that are duplicated multiple times to achieve the desired scalability. When using less than the maximum number of users per Pod, it is recommended that customers evenly distribute users between the Pods to provide the best possible performance. Please consult NetApp SE for exact storage sizing based on your specific requirements. Table 2. Storage Scalability Guidelines for Pod-based Architecture

Scenario Sample Configurations

Number of Persistent Virtual Desktops (Tested Configuration) Number NetApp FAS 2240-2 Arrays(Tested Configuration) Number of Servers Storage Capacity Recommended Total IOPS Available(80 % write, 20% read, 4K) 1 1,000 1 8 8TB 167,472 2 2,000 2 16 16TB 334,944 3 3,000 3 24 24TB 502,416 4 4,000 4 32 32TB 669,888 5 5,000 5 40 40TB 837,360

2. Scale-Up with FAS 3200 or 6200 series arrays

With the scale-up approach, customers use a dual controller NetApp FAS 3200 or 6200 storage array in combination with Atlantis ILIO storage optimization software to scale to a larger number of users. Please

Summary

To summarize, the NetApp FAS Array and Atlantis ILIO storage architecture highlighted in this whitepaper can make VDI simple, scalable, and cost effective for high-performance persistent virtual desktops.

The unique differentiation of the joint NetApp and Atlantis Architecture are:

 1,000 Persistent Desktops with 2U of Storage & Host side IO optimization software  55 IOPS & 30GB per virtual desktop

 Approximately 1 ms write response time with a single controller

 Scale tested with Login VSI & Atlantis Computing Workbench Load Generation Tool to simulate 1,000 users

 Supported for both Citrix XenDesktop and VMware View based deployments

NetApp and Atlantis Computing Architecture Highlights

 Simplicity

o Simple storage architecture, easy to deploy and manage o Automated deployment and configuration

 User Experience

o Better-than-PC user experience

o Efficiently meets all data mobility storage needs  Economics

o CAPEX: Lower total cost than a physical PC

o OPEX: Reduce power, cooling and datacenter footprint  Complete VDI Architecture

o Proven architecture that scales beyond 10,000 users o Enables high availability and disaster recovery

Acknowledgements

Chris Rodrigues, Technical Marketing Engineer, NetApp

Troy Mangum, Senior Manager, Platform and Integrations Engineering, NetApp Abhinav Joshi, Senior Product Manager, Desktop Virtualization, NetApp

Nick Triantos, Global SAN Systems Engineer, Virtualization, NetApp Seth Knox, VP of Products, Atlantis Computing

David Leathers, Senior Solutions Architect, Atlantis Computing Bharath Nagaraj, Solutions Architect, Atlantis Computing

References

Atlantis Computing References

The following guides are available from the Atlantis Computing customer portal:  Atlantis ILIO Persistent VDI Administrator’s Guide

 Atlantis ILIO VMware High Availability Setup Guide

NetApp References

 NetApp's System Performance Modeler (SPM)

 Clustered Data ONTAP Networking Best Practices (TR-4847)  VMware vSphere 5.1 on Clustered Data ONTAP (TR-4068)