Slides from my session on KulenDayz 2016, about best practices in Hyper-V deplyoments.

1. Tomica Kaniški
tomica@kaniski.eu | http://blog.kaniski.eu/
HYPER-V: BEST PRACTICES

2. OUR SPONSORS MADE THIS POSSIBLE!
THANK YOU!

3. TAKE A DEEP BREATH…
"Design/planning phase" is critical!

4. HOW MANY…
• … hosts?
• … CPUs?
• … RAM?
• … bandwidth?
• … ?
• Microsoft Assessment and Planning Toolkit (MAP Toolkit)
– https://www.microsoft.com/en-
us/download/details.aspx?id=7826
– DEMO

5. HOST (HARDWARE)
• use standardized hardware (easier to manage)
• use Windows Server certified hardware (https://www.windowsservercatalog.com/)
• CPU
– server virtualization (Intel VT/AMD-V) and Data Execution Prevention (XD/NX) - Enabled
– SLAT-capable with large cache
– don’t mix vendors (mixed CPU vendors = NO Live Migration)
– Hyper-Threading – enabled
– „compatible”
• performance impact if not using same instruction set
– „best buy” (12-cores per socket?)
• RAM
– ECC-capable
– the more, the better (how many VMs can go down in case of disaster? 30? )
• HDD (local)
– RAID-1 (of two SSDs or HDDs)

6. POWER OPTIONS
• full power or green IT? 
• power settings:
– BIOS/UEFI level
– host OS level
– guest OS level
• easy to set:
– POWERCFG.EXE /S SCHEME_MIN (High performance)
– POWERCFG.EXE /S SCHEME_BALANCED (Balanced (recommended))

7. HOST (SOFTWARE) (1)
• Hyper-V host is a Hyper-V host (and nothing else)!
• install the latest drivers & firmware versions (that work)
– use driver/firmware bundles (like SPP for HP servers) to standardize BIOS, NIC,
storage controllers and HBA versions in your environment
• http://h17007.www1.hpe.com/us/en/enterprise/servers/products/service_pack/spp/index.aspx
• install only the necessary (Hyper-V role, Failover Clustering, MPIO + DSM)
– use MinShell or Core (or even Nano ) installation options
– or full GUI, configure and then „downgrade” to Core
– or just full GUI… 
• updates & hotfixes
– Cluster – https://support.microsoft.com/en-us/kb/2920151
– Hyper-V – https://support.microsoft.com/en-us/kb/3135020
– support will first ask if you’ve installed all the latest and greatest… 

8. HOST (SOFTWARE) (2)
• install backup and monitoring agents
• install antivirus if necessary (company policy)
– don’t forget to set exclusions!
• don’t forget to modify Hyper-V settings after the installation
– default paths are on the system drive!
• Set-VMHost -ComputerName localhost -VirtualHardDiskPath 'D:VMs'
• Set-VMHost -ComputerName localhost -VirtualMachinePath 'D:VMs'
• sign out from Hyper-V hosts when finished working
– we are admins… we love PowerShell… we don’t need RDP
sessions to hosts 
• remember to close remote PS sessions as well 

9. ANTIVIRUS EXCLUSIONS
• antivirus exclusions for Hyper-V hosts & clusters are:
– all directories that contain virtual machines, their disks, snapshots, …
– processes:
• %systemroot%System32vmms.exe
• %systemroot%System32vmwp.exe
• %systemroot%Clusterclussvc.exe
• %systemroot%Clusterrhs.exe
– folders:
• %programfiles%MicrosoftHyper-V*
• %public%DocumentsHyper-V*
• %systemdrive%ClusterStorage*
• %systemdrive%ProgramDataMicrosoftWindowsHyper-V*
• %systemroot%Cluster*
• (witness disk)
– https://support.microsoft.com/en-us/kb/3105657 & https://support.microsoft.com/en-us/kb/961804

10. INSTALLATION
• manual or automatic installation
• speed-up the deployment
– unattend.xml (one-time prepare, many-time use )
– DEMO
– bare-metal host deployment (SCVMM)
– MDT/SCCM deployments
• which version?
– Standard, Datacenter (AVMA)
• which option?
– full GUI, MinShell, Core, Nano?
– full GUI then „downgrade” to Core?
• Remove-WindowsFeature Server-Gui-Shell, Server-Gui-Mgmt-Infra

11. MANAGEMENT TOOLS
• although „real (wo)men” use PowerShell for everything, there are
some other tools that can help you: ()
– Server Manager console
• Best Practices Analyzer (BPA) – useful tool!
– Hyper-V console
• don’t use this one for managing clustered VMs… please 
– Failover Cluster console
• Cluster Validation Wizard – VERY useful tool! (ask Microsoft
Support! )
– System Center VMM
• it works… just fine… but not every time… ()
– 3rd party solutions (5nine, SysInternals, …)

12. VIRTUAL MACHINES (1)
• use/convert to Generation 2 VMs where possible
– https://blogs.technet.microsoft.com/jhoward/2013/11/1
4/hyper-v-generation-2-virtual-machines-part-10/
– Convert-VMGeneration tool
• https://code.msdn.microsoft.com/ConvertVMGeneration
• use only supported guest OSes/versions
– https://technet.microsoft.com/en-
us/library/dn792027(v=ws.11).aspx
• update Integration Components regularly
– some OS hotfixes bring new versions of ICs as well!

13. VIRTUAL MACHINES (2)
• don’t use screen savers inside VMs and sign out of VMs
• templates – use the „smarter” sysprep:
– %systemroot%SysprepSysprep.exe /OOBE /Generalize /Shutdown /Mode:VM
– faster sysprep, a lot less hardware recognizing
– don’t use this templates for multiple virtualization platforms
– Convert-WindowsImage
• https://gallery.technet.microsoft.com/scriptcenter/Conv
ert-WindowsImageps1-0fe23a8f
– offline patching – Apply-WindowsUpdate
• https://gallery.technet.microsoft.com/Offline-Servicing-
of-VHDs-df776bda

14. VIRTUAL MACHINES (3)
• devices:
– don’t use Legacy Network Adapter if it’s not absolutely necessary
– the same goes for virtual HBAs
– remove devices you’re not using
• Automatic Stop Action
– do not leave „Save” – change to either Shut Down or Turn Off
• disable unnecessary background „things”:
– SuperFetch
– Windows Search
– Scheduled Tasks (disk defragmentation, …)
– Aero (optimize for performance)

15. ACTIVE DIRECTORY/GPO
• should I join Hyper-V hosts to Active Directory domain?
– YES (existing or the separate „management” domain – little added
security, but huge management overhead; in highly-secured
environments)
– Hyper-V will work if domain is not available (but Live Migration won’t!)
• should I disable Windows Firewall?
– NO (fine-tune it rather!)
– Group Policy is a great tool, and your host is domain-joined already, so…
• GPO – disable RDP Printer Mapping
– Computer Confguration | Policies | Administrative Templates | Windows
Components | Remote Desktop Services | Remote Desktop Session Host |
Printer Redirection | Do not allow client printer redirection | Enable

16. VIRTUAL MEMORY/PAGING FILE
(PAGEFILE.SYS)
• size – leave it on (automatic) at host level
• move it to separate disk
– for VM – SCSI disk
– exclude this disk from Hyper-V Replica
• you can use the following:
$computer = Get-WmiObject Win32_ComputerSystem -EnableAllPrivileges
$computer.AutomaticManagedPagefile = $false
$computer.Put()
$CurrentPageFile = Get-WmiObject -Query "select * from Win32_PageFileSetting where
name='C:pagefile.sys'"
$CurrentPageFile.delete()
Set-WMIInstance -Class Win32_PageFileSetting -Arguments @{name="D:pagefile.sys";InitialSize = 0;
MaximumSize = 0}

17. CLUSTER
• Hyper-V cluster is a Hyper-V cluster (and nothing else)!
• start with at least 3 nodes
• separate network communication
– Corporate, Storage, LiveMigration, vSwitch, Backup
• use teaming where it seems appropriate
• rename cluster resources (networks, disks) and set network
„roles” & priority in cluster
• Cluster Aware Updating
– use it if it makes sense and don’t use it with SCCM
– http://www.altaro.com/hyper-v/cluster-aware-updating-
hyper-v-basics/

18. NETWORKING (1)
• (re)name your NICs (and NIC teams and vSwitches)
– „Local Area Connection 23” is a great name, but… 
• use teaming (it’s free and it works!)
– should you use Active/Actives?
• it depends (on underlying network… switches and connections
among them – possible link saturation)
• using 1 NIC in Stand-by is just dumb… or not? 
– Dynamic and Switch Independent is the way to go!
• if you have issues with a load balancer, go with Hyper-V port
• which architecture should you use? (converged or not?)
– http://www.hyper-v.nu/archives/hvredevoort/2014/02/definitive-
guide-to-hyper-v-r2-network-architectures/

19. NETWORKING (2)
• no need for a dedicated heartbeat network in cluster
– all cluster networks communicate „heartbeat” signals
• don’t disable VMQ… if you don’t have problems with it
(Broadcom?)
– http://www.dell.com/support/article/us/en/04/SLN132131
• create virtual switches
– … and name them the same (use the convention that works
for you, but same on all hosts)! 
– how many vSwitches do I need?
• smallest number that makes sense (use VLANs!)
• (how many NICs? teamed or not? )

20. NETWORKING (3)
• networking optimizations:
– set the right networking order – Corporate network first
(ncpa.cpl – Advanced – Advanced Settings – Adapters and Bindings)
– disable unnecessary network services
• Live Migration – leave only Client for Microsoft Networks, File and
Printer Sharing, TCP/IPv4 and TCP/IPv6 (NetBIOS is disabled)
• iSCSI – leave only TCP/IPv4 and TCP/IPv6 (NetBIOS is disabled)
– choose which networks will register in DNS (Corporate only)
– set cluster network priorities and roles
– choose Live Migration network(s)
– iSCSI network – use MPIO, not teaming… on separate NICs

21. NETWORKING (4)
• DHCP guard (filtering unsolicited DHCP Server offers)
– enable for all VMs, and disable for the ones that need it
– small performance impact
• Router Guard (filtering ICMP Router Advertisements and
redirect messages)
– not used so much
• implement IPAM for addressing
– instead of those old, boring Excel files 
• do not share adapter with physical OS
• enable Jumbo Frames for CSV, iSCSI and LM networks

22. STORAGE (1)
• single LUN per VM?
– no need… CSVs work just fine
• SAN or SOFS/SMB3?
– if there is SAN in your environment (and it’s supported for Hyper-V), use it
– if you want a „cheaper” solution (and there is no reason against it), try using
SOFS/SMB3
– or a combo (SOFS for SMB3 on SAN LUNs)?
• use 4K native disks and 64K allocation unit size for drives hosting VHD(X)
• avoid vIDE for data disks (Generation 1 VMs)
• use virtual HBAs only if needed
• use Storage QoS if you need it

23. STORAGE (2)
• should I use the „witness” disk in cluster? Yes.
• install MPIO, latest DSMs (usually requires restart) and drivers
• rename the CSV „mount point” (C:ClusterStorageVolume1)”
• put VHD(X)s on CSV into folders!
– access-related errors if there are VHD(X)s in a CSV root!
• NTFS or ReFS?
– NTFS – 64k for VHD(X)s for optimal performance
– ReFS – with Windows Server 2016
• measure IOPS
– http://blog.workinghardinit.work/2014/01/08/how-to-measure-iops-
of-a-virtual-machine-with-resource-metering-and-measurevm/

24. VIRTUAL DISKS
• use/convert to VHDX
• fixed/dynamic/differencing/pass-through?
– VHDX – dynamic
– VHD – fixed-size
• don’t forget to ensure enough free space for dynamic disks!
– the same goes to using thin-provisioned LUNs!
• one-liner:
– Convert-VHD -Path D:VM01.vhd -DestinationPath D:VM01.vhdx -VHDType Dynamic
• don’t use pass-through disks (no point anymore – dynamic disks are
as performant as it gets, and their mobility/manageability is not
questionable
• convert pass-through disk to VHDX
– New-VHD -Path "D:VMSConverted.vhdx" -Dynamic –SourceDisk 5

25. CLUSTER SHARED VOLUMES (1)
• how many and how big?
– minimum of 2 (to utilize two different storage controllers, …)
– < 8 cluster nodes = 1 CSV per 1 node
– > 8 cluster nodes = 1 CSV per 2-4 nodes
• how many VMs per CSV?
– up to 50 (server VMs)
– up to 100 (client VMs in VDI environment)
• IOPS are all that matters!
• enable CSV cache to improve read operations
– (Get-Cluster).BlockCacheSize = 2048
• metadata changes can only occur on the CSV coordinator (owner node)
• please… rename CSVs before you use them!
– C:ClusterStorageVolume1 and C:ClusterStorageVolume2 are great
names, but…

26. CLUSTER SHARED VOLUMES (2)
• set the automatic stop action to anything other than „Save”
• fill up your CSVs with a maximum of 75 percent of its capacity to allow
growth of all these files
• how much space is available on your CSVs?
– http://www.powershellmagazine.com/2014/02/28/reporting-cluster-
shared-volume-csv-disk-space-utilization/
• encrypt CSV with BitLocker – performance impact of 20-30%
• network adapters used for CSVs should have the Client for Microsoft
Networks and File and Printer Sharing for Microsoft Networks enabled
– activate Microsoft Failover Cluster Virtual Adapter Performance Filter (not if
you are using Guest Cluster in your virtual machine – then it should be
disabled on the host level)

27. LIVE MIGRATION (1)
• don't forget to set the live migration network and options
• use Kerberos constrained delegation instead of CredSSP
(need to log on to the server to start live migration)
• enabling KCD for two node cluster is quite easy ():
– HYP1 delegates credentials to HYP2
• $hvhost = "HYP2"
• $domain = "sun.tklabs.eu"
• Get-ADComputer HYP1 | Set-ADObject -Add @{"msDS-
AllowedToDelegateTo"="Microsoft Virtual System Migration
Service/$hvhost.$domain", "cifs/$hvhost.$domain","Microsoft Virtual System
Migration Service/$hvhost", "cifs/$hvhost"}

28. LIVE MIGRATION (2)
– HYP2 delegates credentials to HYP1
• $hvhost = "HYP1"
• $domain = "sun.tklabs.eu"
• Get-ADComputer HYP2 | Set-ADObject -Add @{"msDS-
AllowedToDelegateTo"="Microsoft Virtual System Migration
Service/$hvhost.$domain", "cifs/$hvhost.$domain","Microsoft
Virtual System Migration Service/$hvhost", "cifs/$hvhost"}
• enable live migration
– Enable-VMMigration -Computername HYP1, HYP2
– Set-VMHost -Computername HYP1, HYP2 -
VirtualMachineMigrationAuthenticationType Kerberos
• yes, it can be done through GUI as well! 

29. GUEST CLUSTERING
• use Anti-Affinity rules to make sure nodes don’t end up on the
same physical host
– either VMM or PowerShell
• not available through Failover Clustering console!
• (Get-ClusterGroup KULEN1).AntiAffinityClassNames = "GuestClusterKULEN"
• (Get-ClusterGroup KULEN2).AntiAffinityClassNames = "GuestClusterKULEN"
• Get-ClusterGroup KULEN1 | fl Anti*
• change default failover-triggering heartbeat times (to allow live migrations on
host, without failover actions in guest – default is 10 seconds)
– (Get-Cluster).CrossSubnetThreshold = 25
– (Get-Cluster).SameSubnetThreshold = 25

30. CHECKPOINTS
• Windows Server 2012 R2
– don’t use checkpoints (snapshots) in production
• Windows Server 2016
– use Production checkpoints 
• tips:
– use them as rarely as possible
– checkpoints are no substitution for backups
– delete checkpoints as soon as possible
– don’t delete a checkpoint file on the file level!
• console/PowerShell is the only way to go
– use them with caution on domain controllers and database servers

31. BACKUP AND DISASTER RECOVERY
• backup
– poor man’s backup solution – Windows Server Backup
– other solutions like SC DPM, Veeam, Altaro, …
• no real need to backup Hyper-V hosts
– except maybe for faster recovery, but…
• use Hyper-V Replica if you need disaster recovery
– it’s included anyway
– exclude Paging file disks from replication

32. PERFORMANCE (PERFMON.EXE) (1)
• storage
– it’s all about the IOPS!
– counters:
• Logical Disk(*)Avg. Disk sec/Read
• Logical Disk(*)Avg. Disk sec/Write
– thresholds:
• up to 15 ms should be OK
• 15-25 ms may cause negative impact on workloads
• > 25 ms will cause negative impact on workloads

33. PERFORMANCE (PERFMON.EXE) (2)
• memory
– there has to be enough memory available inside a VM (or a Hyper-V host)!
– counters:
• MemoryAvailable Mbytes
– RAM available for running the active processes
– 15% (or more) is OK
• MemoryPages/sec
– how often the disk is accessed to resolve hard page faults
– < 500 pages per second is OK
– > 500 pages per second – machine just needs more RAM (don’t be cheap!) 

34. PERFORMANCE (PERFMON.EXE) (3)
• network
– counters
• Network Interface(*)Bytes Total/sec
– shows current network utilization
– 20% (or more) free is OK
• Network Interface(*)Output Queue Length
– shows latency in sending network packets (threads that wait on the NIC)
– 0 is OK
– 1 or more is a sign of degraded network performance
• Hyper-V Virtual Network Adapter(*)Bytes/sec
– shows which virtual network adapters are consuming the most bandwidth

35. PERFORMANCE (PERFMON.EXE) (4)
• processor
– counters
• Processor(*)% Processor Time
– overall CPU utilization (at host level)
– < 80% is always OK ()
• Hyper-V Hypervisor Logical Processor(_Total)% Total Run Time
– at host level, but to evaluate guest utilization
• Hyper-V Hypervisor Root Virtual Processor% Total Run Time
– CPU of the root partition
• Hyper-V Hypervisor Virtual Processor(_Total)% Total Run Time
– total time of the virtual processors
• Hyper-V Hypervisor Virtual Processor(*)%Guest Run Time
– CPU of the guest partitions
– always measure the CPU usage of the physical system by using the Hyper-V Hypervisor
Processor performance counters

36. PAL IS YOUR NEW (BEST) PAL!
• PAL (a.k.a. Performance Analysis of Logs Tool)
– reads a performance monitor counter logs and analyzes them using
known thresholds
– for Hyper-V, SQL, IIS, Exchange, SharePoint, …
– you can get it at https://pal.codeplex.com/
– free!
– (P.S. use en-US regional formatting
– (P.P.S. Set-Culture en-US )
– DEMO

37. A FEW MORE THINGS...
• vCPU allocation (Microsoft recommendation)
– no more than 8 virtual CPUs per physical CPU core for server workloads
– no more than 12 virtual CPUs per physical CPU core for VDI workloads
• be careful with thin-provisioned disks (running out of storage space), dynamic memory
(don’t use it for SQL or Exchange)
• Generation 1 VMs – create bigger VHD(X) and smaller partition
– you don’t need to shutdown VM to resize 
• don’t forget common tools like defrag and chkdsk
• set up a naming convention (and stick to it )
• cluster log is your friend… when things go bad (increase sensitivity logging level)
– (Get-Cluster).ClusterLogLevel = 5
– Get-ClusterLog -Destination C:Logs -UseLocalTime
• DOCUMENT EVERYTHING.

38. RESOURCES
• checklists:
– https://blogs.technet.microsoft.com/askpfeplat/2013/11/03/windows-server-2012-r2-hyper-
v-best-practices-in-easy-checklist-form/
– https://blogs.technet.microsoft.com/askpfeplat/2013/03/10/windows-server-2012-hyper-v-
best-practices-in-easy-checklist-form/
• book:
– https://www.packtpub.com/virtualization-and-cloud/hyper-v-best-practices
• other:
– http://www.showit.sk/ShowIT/media/ShowIT/prezentacie/2015/marek_jan_Microsoft-Hyper-
V-performance-tuning.pdf
– http://www.altaro.com/hyper-v/23-best-practices-improve-hyper-v-vm-performance/
– http://www.altaro.com/hyper-v/19-best-practices-hyper-v-cluster/
– http://www.altaro.com/hyper-v/common-hyper-v-deployment-mistakes/
– http://www.altaro.com/hyper-v/hyper-v-virtual-cpus-explained/

39. THANK YOU!