View Sizing and Best Practices

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Agenda

1. VDI Sizing Methodology

Study the Worker Profile

Design Server and Storage Architecture

Assess Performance

2. Server and Storage Sizing Best Practices

3. Add-on View 3 Reference Architecture

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VDI Sizing Methodology- Study the Worker Profile

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VDI Capacity Planning

Proper sizing is critical to successful VDI project

Affects TCO/ROI

Affects end-user experience

VDI technology advancing at rapid rate

Sizing considerations changing rapidly

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Step 1: Measure Physical Desktop Usage

Study usage patterns of physical desktop (perfmon)

VMware Capacity Planner can also be used

We measured typical desktop running common apps (Word, Excel, PPT, Adobe, IE, VirusScan)

Resource Measurement

CPU Usage Perfmon: Processor\% Processor Time

Memory Consumption Perfmon: Memory Available Mbytes

Storage ThroughputStorage IOPS

Perfmon: Physical Disk\Bytes Transferred / secPerfmon: Physical Disk\Transfers / sec

Network Throughput Perfmon: Network Interface: Bytes Transferred / sec

Resource Measurement Measured value

CPU Usage Perfmon: Processor\% Processor Time 2.79%

Memory Consumption Perfmon: Memory Available Mbytes 254MB

Storage ThroughputStorage IOPS

Perfmon: Physical Disk\Bytes Transferred / secPerfmon: Physical Disk\Transfers / sec

1177605 IOPS

Network Throughput Perfmon: Network Interface: Bytes Transferred / sec 245

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Step 2: Estimate CPU Requirements

Examine physical usage patterns

Perfmon data provides CPU requirements from physical desktop

Observed 130MHz average on physical desktop

Targeting 64 virtual desktops per server (8 VMs per core)

64 VMs x 130MHz = 8.3 GHz

Additional considerations when virtualizing

Storage virtualization

Network virtualization

Connection protocol

Additional headroom for spikes

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Step 3: Estimate Memory Requirements

Examine physical usage patterns

Memory allocated: 512MB

Memory consumed: 258MB

Additional Considerations when virtualizing

ESX can reduce memory requirements due to ESX page sharing

Windows XP can be reduced to 125MB footprint on ESX

Similar reductions on ESX from common applications

Application/Program Unique Memory Usage

Windows XP 125 M

Windows Vista (SuperFetch off) 175 M

Microsoft Word 15 M

Microsoft Excel 15 M

Microsoft PowerPoint 10 M

Microsoft Outlook 10 M

XP Pro SP2: 4x1GB

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Time (min)

Mem

ory

(M

B)

Non-ZeroZeroBackingPrivate

Memory footprint of four idle VMs quickly decreased to 300MB due to aggressive

page sharing.

Memory footprint of four idle VMs quickly decreased to 800MB. (Vista has larger

memory footprint.)

Vista32: 4x1GB

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Time (min)

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ory

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) Non-Zero

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Private

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Step 3: Estimate Memory Requirements (Con’t)

High watermark (no page sharing)

64 VMs * 512MB = 32GB

Low watermark:

64 VMs * 125MB (Win XP) = 8GB

64 VMs * (15MB Word) = 1GB

64 VMs * (15MB Excel) = 1GB

64 VMs * (10MB PowerPoint) = 1GB

64 VMs * (Adobe, IE, Winzip) = 3GB

64 VMs * (VM memory overhead) = 3GB

Low watermark 17GB

Potential range from 17GB – 32GB

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Step 4: Estimate Network Requirements

Examine physical usage patterns

Estimated traffic / NIC speed = # of NICs

Perfmon showed 245 bytes/sec average on physical desktop

64VMs x 245 bytes/sec = 3920 bytes/sec

Additional considerations when virtualizing

Remote display protocol

Shared, redirected folders (My Documents etc.)

Printing

Multimedia

Multi-port NICs, bus speed (PCI, PCI-X)

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Step 5: Estimate Storage Requirements (Capacity)(Size of vmdk) + (VM RAM) + (suspend/resume) + 100MB per VM for logs)

Sample calculation for 64 VMs (32 VMs per LUN):

32 VM * 10GB per VM (vmdk) = 320GB

32 VM * 512MB (VM RAM) = 16GB

32 VM * 512MB (suspend/resume) = 16GB

32 VM * 100MB (logs) = ~4GB

356GB

356GB + 15% free space = 410GB

410GB x 2 LUNs (32 VMs per LUN) = 820GB

**Does not include space for user data

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Step 5b: Estimate Storage Requirements (Performance)

Examine physical usage patterns

Perfmon showed 5 IOPS and 115KBps (average)

64 VM x 5 IOPS = 320 IOPS

64 VM x 115 KBps = 7360 KBps

Additional considerations when virtualizing

Other systems/VMs sharing same spindles

VMware ESX disk I/O

Boot periods, desktop search, defrag, virus scan etc

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Summarizing the Worker Profile

Minimum estimated CPU:

8.3GHZ + virtualization (typically 5-10%)

Minimum estimated memory:

17-32GB (dependent on page sharing across VMs)

Minimum estimated network:

16KBps + virtualization

Minimum estimated storage:

820GB

320 IOPS / 7360 KBps

**Based on study of physical desktop

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Design Considerations for Server and Storage Architecture

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Server Architecture Considerations

Traditional rack-mount or blade?

Blades offer smaller datacenter footprint

Higher up-front cost

PCI slots (quantity, PCI-X/PCI-E, redundancy)

CPU/Memory

Target CPU utilization (typically 65-80%)

Processor family (VMotion compatibility)

# of sockets/cores vs. qty/cost of RAM

Impact of single server failure

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Storage Architecture Considerations

Protocol (FC, iSCSI, NFS)

Existing infrastructure

Tiered solutions (i.e. FC for system drives, NAS for data drives)

How many virtual machines per LUN?

30-40 .vmdk for average I/O VMs

15-20 .vmdk for heavy I/O VMs

Highly dependant on storage array:

http://www.vmware.com/resources/techresources/1059

Disk drive rotational speed and capacity

Read/write mix, RAID type

VMware ESX boot-from-SAN

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Comparing Disk Drive Models (Speed/Capacity)

Calculating required spindles – example 1 (146GB 10K drive):

820GB / 146GB (RAID 5) = 7 drives (approx)

320 IOPS / 130 IOPs per drive = 3 drives (approx)

Capacity requires 7 drives

Drive Speed IOPS (8KB random mix)

5,400 RPM ATA 50 IOPS

7,200 RPM ATA 60 IOPS

7,200 RPM SATA 80 IOPS

7,200 RPM LCFC 80 IOPS

10,000 RPM FC 130 IOPS

15,000 RPM FC 150 IOPS

Calculating required spindles – example 2 (500GB SATA drive):

820GB / 500GB (RAID 5) = 3 drives (approx)

320 IOPS / 60 IOPs per drive = 6 drives (approx)

Performance requires 6 drives

Sample disk drive performance stats:

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Data Center Architecture Considerations

Datacenter design considerationsBalance cost, # of VMs, and # of VMware ESX to manage

Use a dedicated ESX cluster for VDI?

Integrate into existing cluster?

Configuration maximumsMax 128 vCPUs per VMware ESX

Max 20 vCPU per core

Max 32 servers per HA/DRS cluster

256 VMFS volumes per server

200 ESX hosts per Virtual Center server

2000 virtual machines per Virtual Center server

http://www.vmware.com/pdf/vi3_35/esx_3/r35/vi3_35_25_config_max.pdf

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Virtual Desktop Considerations

Choosing an operating system

Windows XP (512MB or higher)

Vista (1GB or higher)

Choosing resource allocations

# of vCPU

Quantity of RAM

Choosing Storage requirements

System drive capacity (GB)

Data drive capacity (GB)

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Sample Building Block

PowerEdge 2950

2 x quad-core Xeon 2.7GHz

32GB RAM

ESX 3.5.0 Update 2

Dell PS5000X

146GB 10K drives

RAID 5

32 VMs per public NIC

32 VMs per s/w iSCSI LUN

Windows XP SP2

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VDI Sizing: Assess Performance

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Simulating VDI Workloads

Capacity planning is difficult but critical

True human activity is difficult to replicate

Requirements for simulating VDI workloads

Must be repeatable

Must be measurable

Must be scalable

Must closely resemble human PC usage patterns

Must be tunable via parameters

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Workload Based on AutoIT

Freeware for simulating Windows GUI

http://www.autoitscript.com/autoit3/

Executes the following:

1. Word (open, modify random pages, save and close)

2. Excel (writing to cells, sorting, formulas, charts)

3. PowerPoint (slideshow and edit slides)

4. Adobe Acrobat (Open and browse random pages)

5. Internet Explorer (browse plain-test and web album)

6. Winzip (install/uninstall)

7. McAfee VirusScan (continuous on-access scan)

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Assess Performance

Tools for performance monitoring

Esxtop

vscsiStats

PS Series Monitor (beta)

Areas to watch for:

CPU: % Processor time

Memory: Free Mbytes, page sharing, swapping

Network: Bytes Transferred

Disk: Reads and Writes/Sec (IOPS), throughput (MB/s)

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CPU observations – Steady State

8 cores @ 2.67GHz

Averaged approximately 55%

High spikes observed

s/w iSCSI: 55%

h/w iSCSI 49%

Headroom available

**Does not include display protocol

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Memory Observations – Steady State

32GB physical RAM

64 VMs (512MB RAM each)

Identical OS/apps

Average consumed: 19GB

Page sharing: 13GB

No ESX swapping observed

Page sharing increased/decreased as common apps were opened/closed

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Storage Observations

Steady State Bursty disk I/O

Mainly due to opening/closing apps

IOPS (Estimated 320)

185 average

650 peak

Throughput (Estimated 7360):

3530 average

13733 peak

Potential bottleneck if not sized correctly

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Measuring In-guest Timing

AutoIT allows in-guest measurements

Helps to validate end-user experience

Shows scalability as more virtual desktops are added

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Best Practices for Server and Storage Sizing

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Sizing Best Practices - Server

CPU recommendations

Dual socket (quad-core) offers nice balance on cost/performance/ROI

Current max of 128 vCPUs per ESX host

Increasing in upcoming ESX release

Memory recommendations

Maximize page sharing (same OS/applications and version)

Effectively leverage over-commit, avoid swapping

Plan for virtual machine memory overhead

84MB for each 32-bit VM with 1GB RAM

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Sizing Best Practices - Storage

Base capacity formula:

(Size of vmdk) + (VM RAM) + (suspend/resume) + 100MB per VM for logs)

Does not include data drives

Understand the workload:

Relatively low I/O in normal operation

Our workload showed mostly 4KB random I/O

Plan for spikes:

OS patching - stagger, off-hours

Manual virus scan – use on-access scans

Desktop search

Defrag

Cold boot, suspend/resume

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Sizing Best Practices - Storage

Understand disk drive technology in VDI solutions

Larger capacity drives typically offer lower performance

Compounded during boot storm, virus scan storm etc

Sizing for peaks vs. averages

SLAs influence design choices

Size for capacity (GB) and performance (IOPS, throughput)

Light I/O workload makes s/w iSCSI viable

Note: No ESX boot-from-SAN with s/w iSCSI

Engage your storage admin in the design process

Perform storage admin tasks during off-hours

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Sizing Best Practices – Storage

Minimize storage footprint

Separate applications from OS (ThinApp)

nLite and vLite to streamline guest OS

Thin provision storage

Virtual machines or entire datastore

Single instancing (de-duplication)

Array-based snapshots

Desktop Composer

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Sizing Best Practices – Guest OS

Remove unnecessary services, device drivers, add-on’s

nLite (XP), vLite (Vista) to optimize the OS build

Disable graphical screen savers

Desktop images should be disposable

Use centralized file storage

Redirect Application Data. Cookies, Favorites, Templates

Roaming/virtualized profiles

Use LSILogic SCSI driver

…http://www.vmware.com/files/pdf/XP_guide_vdi.pdf

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Sizing Best Practices - Performance

ESX Best Practices for Performance

http://www.vmware.com/pdf/vi_performance_tuning.pdf

Disable USB, COM, CD, floppy etc (guest and host)

Deploy SMP guests sparingly

Additional vCPUs add overhead

Over-commit memory can be effective with VDI

Avoid ESX swapping

Monitor performance through esxtop

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Future Work …

Studying RDP overhead

Integration with View Manager Server

Integrating additional applications

Outlook (cached mode, online mode)

Scalable Virtual Images (SVI)

Vista

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View3 Reference Architecture

http://www.vmware.com/resources/wp/view_reference_architecture_register.html

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The Goal is to provide Components

Quicker implementation, reduced costs, and minimized risk

Standard

Scalable

Validated

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1000 VMs Building Bloc

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5000 VMs POD

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Assessment on 1000 VMs

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Infrastructure

8 VMs /core64 VMs / LUNs

7 LUNs / Clusters

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Measurement (sample)

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Measurement

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Q&A

Questions ?