Server Virtualization Technologies: Uses, Comparisons, and Implications

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Server Virtualization Technologies Uses,
Comparisons, and Implications
University of Michigan Administrative Information
Services

• David Sweetman
• Windows Enterprise Systems Admin
• Administrative Information Services
• University of Michigan
• dsweetma_at_umich.edu

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Presentation Overview

• The What and Why of virtualization
• Comparing Product Features
• Comparing Product Performance
• Evaluating Physical Servers for virtualization
• Costs
• Questions

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What is server virtualization?

• Creating multiple logical server OS instances on
  one physical piece of hardware
• All HW drivers are virtualized same virtual HW
  regardless of physical HW
• Each virtual machine is completely independent of
  the others and doesnt realize its virtualized

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Why virtualize?

• More efficient HW utilization
• More efficient staff
• Long-term matching resources needs
• Quick and nimble server provisioning
• Testing Troubleshooting
• More effective redundancy
• HW maintenance w/o app downtime
• Simplify system imaging
• Disaster Recovery

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HW Utilization Facts

• Individual ebb and flow of resources
• Cumulative usage of 28 servers in the MAIS data
  center evaluated for virtualization
• 44GB RAM, 138.15Ghz CPU, and 1323GB HD

• 45 of RAM not used 99.9 of time.

• 25 of RAM never used concurrently.

• 85 of CPU not used 99.9 of time.

• 81 of CPU never used concurrently.

• 68 of hard disk space unused

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Hard Disk Utilization

• More Efficient Hard Disk Utilization
• Total 1323 GB
• Used 418 GB
• Free 905 GB
• (68 unused)
• SAN in 30GB chunks
• 1 fibre channel gt1 server
• Virtual HDs more granular
• Share free space allocate as needed

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Virtualization vs. Consolidation

• Virtualized servers separate OSes
• Consolidation same OS
• Virtualized servers must each be administered,
  patched, etc.
• Consolidated applications can introduce conflicts
  and support issues

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Virtual Host Licensing

• Windows and other Microsoft per-server apps are
  licensed per virtual server. (1 physical server
  w/ 6 virtual Windows servers 6-7 licenses
  needed)
• As of 4/1/2005, Microsoft per-processor licenses
  are per physical processor (1 physical server w/
  3 virtual SQL Servers sharing 1 CPU 1
  per-processor license)
• Virtualization savings are not in licenses.
• Check with other vendors.

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Virtualization Software

• MS Virtual PC 2004 workstation only
• VMWare Workstation 5 workstation only
• MS Virtual Server 2005, Standard (4p)
• MS Virtual Server 2005, Enterprise (32p)
• VMWare GSX Server 3.1
• VMWare ESX Server 2.5

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Common Features

• Up to 3.6GB RAM per virtual host
• Web-based console for administration
• Host OS sees HT CPU, virtual do not
• VMs consist of 1 config file 1 file / HD
• VMs can mount physical CDs or ISOs
• VMs can be multi-homed
• Up to 64 VMs per host server
• Highly scriptable extensive API
• Granular permissions for individual VMs
• Detailed logging

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MS Virtual Server 2005

• Targeted to increase efficiency in testing and
  development, and re-hosting
• Up to 1 processor per virtual host
• Windows underlying host OS
• Only Windows VMs supported
• No USB support
• 2 processor SMP coming soon

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VMWare ESX Server 2.5

• Targeted at mission-critical enterprise services
• Up to 2 processors per host
• Custom Linux underlying OS
• Windows Linux VMs supported
• Dedicated NIC for admin (2 total min)
• USB support
• 4 proc SMP coming soon

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Do I need to know Linux?

• VMWare ESX Server is based on Linux
• All administration is possible through web
• Dont need any Linux experience for installation
  or ongoing admin
• SSH and SFTP access to server
• Used?
• Installed backup software
• sFTPed ISOs to server

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Managing Virtual Servers

• Web site is primary interface
• Attach to VM console
• Virtual Server ActiveX control
• VMWare separate application
• Reboot, power on, power off
• Create and manage VMs
• Allocate hardware resources
• Mount CDs and floppies
• View recent performance data

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VS Screenshot
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VMWare Screenshot
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Hyper-threading

• One physical CPU seen as 2 logical
• Both products see HT, non-HT VMs
• Slows virtualization performance
• 1 HT CPU lt 2 Phy CPU
• 0-20 performance increase over no HT
• http//www.intel.com/technology/hyperthread/

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RAM Allocation

• Virtual Server Max lt total physical
  memory
• VMWare Max ltgt total physical
• RAM Ballooning
• RAM pooled across multiple VMs
• Enables more efficient RAM utilization
• If max out, goes to paging file

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VS Screenshot
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VMWare Screenshot
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Monitoring

• MOM (or other host monitoring) Monitors VMs like
  physical
• Virtual Server MOM Management Pack
• Integrates into MOM framework
• Monitor overall host and VM servers
• VMWare vmkusage
• VMWare VirtualCenter
• Database back-end across all servers

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Virtual Center

• Central monitoring and management in VMWare
  environment
• Manage all VMs from one interface
• Additional software / license
• Management application
• Set thresholds and actions like MOM
• SQL or Oracle DB backend
• Assign privileges via NTFS

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Virtual Center Screenshot
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Converting Physical Server

• Both MS VMWare offer tools to create virtual
  systems from physical
• Physical HW drivers replaced by VM
• Ideal for the truly unique server (highly
  customized)
• Both vendors recommend loading virtual servers
  from scratch
• Slow for both vendors 6h / 4GB image
• VSMT (Virtual Server Migration Tool)
• many prereqs (DHCP, ADS, SQL)
• Not in one month eval
• P2V (Physical 2 Virtual)
• Simple boot CD and server piece
• Licensed per use

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VMotion

• Enables seamless transition of live virtual host
  between physical servers
• Dynamic Resource Allocation across servers
  respond to load changes
• HW maintenance

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Best Practices

• Plan out server allocations
• Create gold image base OS kept up-to-date
  patches duplicate for new VMs
• Use ISOs for CD access
• Use standard backup and restore
• Take system images as needed

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Summary of VMWare differences

• More comprehensive web GUI (for example, deleting
  hosts HDs)
• Support for dual processor virtuals
• Support for Linux virtuals
• Virtual Center central management
• Easy-to-use physical-to-virtual support
• VMotion seamlessly move virtual servers between
  physical hosts

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Testing Environment

• One month each was spent evaluating MS Virtual
  Server VMWare ESX Server
• Identical testing was attempted on each. Load
  and usability testing Win 2000, 2003, IIS5,
  IIS6, SQL Server 2000, 3rd party apps
• Test hardware
• 1.4Ghz x 4 physical processors (8 w/ HT)
• 8GB of RAM
• 60GB fibre-channel connected SAN space

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Performance Comparisons

• Automated load test of Aspen 2.5 dev environment
  (Win 2000/IIS5 Win 2000/SQL 2000)
• Citrix / TS load test w/ Helpdesk
• IIS6-based memory, CPU, disk, and network I/O
  testing
• SQL Server add, update, and delete testing
• Load testing both as isolated server and with
  other virtual server processing
• Normal usage w/o issue in all cases

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Performance Comparisons

• Windows 2003 IIS6 and SQL 2000 perf compare

• VMWare CPU hyper-threaded related, 93 w/o
• VS SQL VS 2005 SP1 has performance enhancements

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Performance Comparisons

• Previous stats were isolated tests
• VMs wont be alone on physical host
• How does system perform w/ other VMs running
  assorted, intensive tasks?

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IIS/SQL Load Test Results

• Mercury LoadRunner scripted test
• Overall performance
• 100_at_30/min VM 60
• 1000_at_12/min VM 99
• What made it slow?
• CPU queuing
• Memory, HD, NetIO nearly identical

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Terminal Services / Citrix Load Test Results

• Currently 14 servers, 4procs (8HT), 4GB RAM load
  balancing 700 concurrent
• CPU and RAM intensive apps
• 60 users max per physical server
• CPU bottleneck (logon BusObj)
• 1CPU 7 users max 2 CPU 12 max
• 100 v 1CPU or 58 v 2CPU to match 14 physicals
• Recommendation 2 CPU only for small use

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Business Objects WebI dev
Win 2000 / IIS5 / 2400MB RAM / 1.4Ghz x 2 (no HT)

• Virtualize? Yes. 900 / 1.4Ghz

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PSoft 8 Fin Crystal/nVision Dev
Win 2000 / 2300MB RAM / 1.1Ghz x 2 (no HT)

• Virtualize? Yes. 900 / 1.4Ghz

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PSoft8 HE Crystal/nVision - Prod
Win 2000 / 1500MB RAM / 2.8Ghz x 1 (w/ HT)

• Virtualize? NOT at this time CPU needs too high

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sumTotal Aspen 2.5 eLearning
Win 2000 / SQL 2000 / 2358MB RAM / 1.9Ghz x 2 (w/
HT)

• Virtualize? Yes 2300MB / 1.4Ghz x 2 Note
  high NICsync CPUimp/exp

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Domain Controllers
Win 2003 / 2000MB RAM / 700Mhz x 4 (no HT)

• Virtualize? Yes 850MB / 1.4Ghz

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Univ of Michigan - Flint

• VMWare ESX Server
• Determining factor Linux support MS Virtual
  Server wasnt available
• Several years of experience, starting with GSX,
  public web services, online teaching, real video
  server, internal file/print, 46v on 5 physical
  (15 on 1), lt10 slower, Dell 2650s 4600s, 2
  proc, 12GB RAM

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NC State University

• MS Virtual Server 2005
• Determining factor Cost
• PeopleSoft v8 Crystal/nVision app servers 18
  virtual servers, 7 physical servers, dual Xeon
  gt2GB, physical v. virtual head-to-head, little
  difference in performance.

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Potential Uses from Previous Presentations

• NAP - Remediation Servers Big Red Button for
  critical fix assign additional resources
• Keynote - Reliability one of pillars of
  Trustworthy Computing
• Boston U Matt - NetReg peak usage first couple
  weeks of semester
• WSUS 3Ghz, 1GB RAM recommended sitting idle
  most of time?
• Decrease dev system allocation in busy times

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Pricing

• MS Virtual Server 2005 (4CPU Server, 8GB RAM)
• Win 2003 Std up to 4 processors, Ent up to 32
• VS Std 4proc/4GB Ent 8proc/32GB
• 2003 Ent/Std 500500 1000
• VMWare Server ESX (4CPU other pricing scales)
• ESX 4500/phy server 945/yr support
• ESXSMPV-agents 6000/phy server
  1764/yr support
• VMWare Add-ons
• VirtualCenter server 3000 1050/yr
• P2V Starter kit (25) 2000 420/yr

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Cost / Benefit Example

• VMWare Server ESX
• 45K separate HW purchase price
• 29K 2K/yr (ESX w/SMP) 35
• MS Virtual Server Std
• 33K separate HW purchase price
• 30K virtual HW software 10
• Note In both cases, estimates are conservative

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Summary / take-aways

• More effective resource utilization and response
  to changing needs (5-15 to 60-70)
• Virtual Server VMWare comparable performance,
  VMWare more isolated
• VMWare more feature-rich SMP, VMotion, manage
  multiple servers
• VMWare costs more, but you can do more,
  virtualize more costly servers
• Both platforms have limits, active improvement

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Other Resources

• VMWare www.vmware.com
• Virtual Server www.microsoft.com/virtualserver/
• Rapid App www.rapidapp.com

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David SweetmanUniversity of Michigandsweetma_at_umi
ch.edu
Questions?