real world vdi optimization - snia · vdi optimization – real world learnings © 2012 storage...

VDI Optimization – Real World Learnings

Russ Fellows, Evaluator Group

VDI Optimization – Real World Learnings © 2012 Storage Networking Industry Association. All Rights Reserved.

SNIA Legal Notice

The material contained in this tutorial is copyrighted by the SNIA unless otherwise noted. Member companies and individual members may use this material in presentations and literature under the following conditions:

Any slide or slides used must be reproduced in their entirety without modification The SNIA must be acknowledged as the source of any material used in the body of any document containing material from these presentations.

This presentation is a project of the SNIA Education Committee. Neither the author nor the presenter is an attorney and nothing in this presentation is intended to be, or should be construed as legal advice or an opinion of counsel. If you need legal advice or a legal opinion please contact your attorney. The information presented herein represents the author's personal opinion and current understanding of the relevant issues involved. The author, the presenter, and the SNIA do not assume any responsibility or liability for damages arising out of any reliance on or use of this information. NO WARRANTIES, EXPRESS OR IMPLIED. USE AT YOUR OWN RISK.

2 2


Storage is the Heart of VDI

3

* Network plays key role, but is typically not bottleneck in local VDI deployments


VDI Guidance

Vendors Provide good info for Server and Network Guidance regarding Storage for VDI is limited:

Capacity : Varies for pooled / persistent (20 GB persistent) Performance : Use 8 – 12 iops as an average

The Problem Workload claims are inaccurate

Claims of 8 IOPS / client are highly generalized Read / write ratio’s shift towards read for heavier use

A real VDI I/O is different than a synthetic I/O A real I/O cab be up to 2 MB, synthetic i/o tests use 512 Bytes Queuing theory dictates 2X headroom needed to manage peaks

4


Barriers to VDI Adoption

May Require Active Network Connectivity Local mode removes this limitation

Capital Investment Storage costs may exceed expectations Capital costs typically exceed traditional approach Storage configuration is critical to cost and performance

Concerns over Technology or Approach Users dislike lack of control (particularly with pooled) Concerns over performance and flexibility

5


VDI STORAGE CONSIDERATIONS

The impact of VDI on Storage

6


VDI Architectural Choices

Persistent Desktops Fully personalized Individual application stacks for each user

Linked Clones Could not be personalized (persona with View 5) Uses snapshot of a VM to as baseline desktop instance Builds remainder of desktop pool from gold-image

Tradeoffs Space and performance efficiency with Linked Clones Users want personalization (some need customized apps)

7


Persona Layering

8

Customization Objects

User Apps User Data User Persona

MS Office 2010

MS Office 2003

Adobe CS5

Visual Studio

Firefox

Symantec AV

Application Pool

Win7 64

MS Office 2010

Symantec AV

Firefox

User 1

Rea

d O

nly

Wri

teab

le

User Apps

User Data User Persona

Win7 x86 Win7 64 Win XP

OS Pool


Performance Considerations

Server HW : Sizing Guidelines Good Starting Point Hypervisors & Brokers : Currently 2 major hypervisors and 2 brokers in the market Storage : Many issues - Covered next Networks:

LANs : 1 Gb to desktop is sufficient in most cases SANs : Dedicated storage network for iSCSI, NFS, FC or FCoE part of storage considerations WANs : Remote VDI use can be problematic without “disconnected” or “checkout” of instances

9


STORAGE PERFORMANCE FOR VDI

10


VDI Storage Performance

Existing Deployments show Storage is Critical for Performance Issues:

Difficult to rationalize vendor claims Vendors claim a “VDI user” at a $ BUT, there is no common measurements, configuration or workloads to make those claims

Existing VDI tools test entire system Requires extensive server, network and software setup Considerable expense (100’s of servers)

Existing storage benchmarks do not recreate VDI workload

11


Actual VDI Transfer Sizes

12


The VDI – POC Dilemma

Proof of Concept Issues: Proof of Concept can be costly Typically requires all server, network and storage Extensive setup time (can be multiple weeks)

Recommendation: Use full tools : Large projects where Network, CPU and Memory are issues, use existing tools Storage VDI : When storage is primary concern, or where time and resources are constrained

13


VDI Performance Testing

VDI-IOmark Login VSI View Planner SPC

What it tests Storage Entire System Entire System Storage

Workload 100% real VDI

100% real VDI

100% real VDI Non VDI

Cost No cost for

Users – Vendors pay

Cost to license VMware

partners only

Cost to license & publish

Equipment Required Low High High Low

Setup Time Low High High Low

14


VDI Storage Benchmark

VDI-IOmark - A storage specific benchmark for VDI Tests storage only Accurate workloads based on actual VDI users

Uses “I/O replay” to simulate storage I/O patterns

Storage Agnostic Supports any storage supported by hypervisor

Reduces Infrastructure 10X Reduction in capital requirements and test setup Each server can test up to 1,000 VDI users

12 CPU, 96 GB RAM, with multiple I/O ports

15


VDI-IOmark Methodology

Benchmark Creation Real world VDI environment used for data capture Actual I/O captured in VDI configuration and workloads

Benchmark Run Utilize driver to replay workloads (I/O replay) Does not require applications

Result Reporting Results indicate number of users supported Benchmark runs and results audited by EGI for consistency Storage configuration options are included in report

16


REAL WORLD VDI EXAMPLES

17


Fortune 50 – Firm #1

18

Currently have 10K seats, want 50K in 1 year Use concept of “Pods” for scalable unit 1 Pod = 1 rack

Supports approximately 3,000 VDI instances Capex = $2.3 M, Storage about 33% of total cost

Using predominately persistent VDI images Image management is an issue Investigating Cloning / Layering, sees it as promising

Goals Want improved image management Lower storage to 25% of total cost Want Virus scan offload, with minimal storage impact


Fortune 500 - Firm #2

19

Using VDI for Mixture of Employees Both office workers and engineers Office = pooled, engineers = persistent

Issues: Engineering design processes stress storage during compilations

Solution: Overprovision memory, use swap to SSD RAM drive in guest OS for compile space


Real World Findings

20

Storage was Major Cost and Performance Driver Products provide unknown price / perf. Must overprovision spindles to achieve performance

VDI Applications Generally consistent apps for office workers (MS Office) Understand system wide impact of special purpose apps

Desires: Improve price / performance of storage Modular, easy to deploy building blocks to scale Improve POC and performance validations


VDI RECOMMENDATIONS

21


VDI – Networks

LAN Issues: Consider flat, layer 2 network to alleviate multi-hop and ISL limitations of traditional LANs

SAN Issues: Dedicated SAN not required, but must have dedicated QoS Storage protocols do matter

FC has excellent latency with low CPU overhead NFS provides good parallelism of protocol and access to .vmdk’s iSCSI can provide good performance, configuration is critical

WAN Issues: WAN access still a factor for VDI, consider alternatives

22


VDI – Memory & Storage

Memory Overuse can have Dramatic Impact on Performance and Storage Utilization

Swapping / Paging is almost always bad

Use Windows Paging File : If hypervisor doesn’t permit memory overcommit If hypervisor doesn’t support swap to SSD

Do not to use Windows Paging : If Hypervisor supports overcommit and swap to SSD

Hypervisor can use memory more efficiently Also can swap to SSD is much faster than OS paging

23


Hypervisor Memory Mgmt.

24

Page Sharing • Multiple VM’s sharing a single

page of memory

Memory Overcommit • Uses OS’ native memory

management indirectly

Memory Compression • On-the-fly compression on

a per page instance


Hypervisor I/O Overhead

Hypervisor Queuing can Occur at High Loads Seen instances where hypervisor kernel is adding 200 – 500 ms of delay to I/O

SSD Storage may Highlight Inefficiencies’ Fast storage makes other components look slow

Recommendations: Spread workload over more devices or files Storage access protocols have an impact (FC, iSCSI, NFS) Multiple SCSI controllers, multiple paths Use raw device as last resort

RDM in VMware, Direct LVM, Pass-through

25


Performance Requirements

Architecture for I/O Optimization Persistent vs. Non-Persistent : Understand Storage Impact When to use Hypervisor tools vs. Storage tools

Requires use of Solid State Storage On a $ / iops basis, SSD and Flash less expensive Use of Solid State limited to master image Use Traditional storage for changes (i.e. writes)

Caching Appliances may Improve Performance Virtualization and VDI specific Storage

Vendors include: (Whiptail, I/O Turbine, Virsto, Atlantis Computing, Nimble Storage, Tintri, etc.)

26


VDI Storage Best Practices

Use Clones when Possible Either pools, or linked clones on VM Or, utilize storage writeable clones

Separate Master Image from Other Data Place Master Image on Solid-State

Ensure master image resides on Solid-State Either VM or Storage Cloning may work

Maintain differences in separate disk area Swap / page area, User profile data, etc. This data should be places on spinning media

27


VDI Best Practices – Cont.

Separate OS and User Data (good advice generally) Utilize Some form of Writeable Clones

Layering technologies Hypervisor based clones Storage writeable clones

Utilize VAAI storage API’s if available Space Efficiency via Clones or Thin Provisioning MUST Utilize SSD for Some Portion of Data

Using clones concentrates I/O’s for reads Use Solid State for golden image read data (10 – 20 GB)

28


Storage for VDI

Storage Performance Solid state as storage Wide Stripping VAAI Large cache (read &write) Auto-tiering Do not use hypervisor snaps Nice to Have:

Storage snapshots (vs. hypervisor snapshots which impact performance)

Storage Efficiency Layering Technologies Writeable Storage Clones Thin Provisioning Little Impact:

Deduplication (if using clones or pooled VDI instances)

29


Real World VDI Conclusions

Ranked Impact of Choices on Performance: 1) Architecture, 2) Storage, 3) Hypervisor & Broker, 4) Networks, 5) Server HW

First: Understand Architectural Implications Pools, persistent and layered images, storage implications

Next: Optimize Storage Investigate methods to reduce storage capacity Optimize for performance (SSD, tiering, caching, etc.)

Choose Hypervisor & Broker Optimize Network to Support These Choices

30

VDI Optimization – Real World Learnings © 2012 Storage Networking Industry Association. All Rights Reserved. 31 31

Attribution & Feedback

Please send any questions or comments regarding this SNIA Tutorial to [email protected]

The SNIA Education Committee would like to thank the following individuals for their contributions to this Tutorial.

Authorship History

Russ Fellows: Original Presentation - Fall 2011 Updates: New Layering, Hypervisor Performance and Case Studies added

Additional Contributors

mailto:[email protected]�


THANK YOU!

For more Information contact: Russ Fellows : [email protected]

32

mailto:[email protected]�

real world vdi optimization - snia · vdi optimization – real world learnings © 2012 storage...

Documents