Microsoft Virtual Academy
Module 3
Creating and Managing Virtual Hard
Disks, Virtual Machines, and
Checkpoints
Module Overview
• Creating and Configuring Virtual Hard Disks
• Creating and Configuring Virtual Machines
• Installing and Importing Virtual Machines
• Managing Virtual Machine Checkpoints
• Monitoring Hyper-V
Lesson 1: Creating and Configuring Virtual Hard Disks
• What Are the Storage Options for Virtual Machines?
• Overview of the Hyper-V Virtual Hard Disk Formats
• Fixed Size and Dynamically Expanding Virtual Hard Disks
• Differencing Virtual Hard Disks
• Directly Attached Storage
• Virtual Hard Disk Sharing and Quality of Service Management
• Hyper-V Considerations for Virtual Hard Disk Storage
What Are the Storage Options for Virtual Machines?
• Virtual hard disk and directly attached disks
• Support two storage controller types:
IDE
SCSI
Only for Generation 1 virtual
machines
For Generation 1 and
Generation 2 virtual machines
Two controllers—Two devices
per IDE controller
Four controllers—64 devices per
SCSI controller
Virtual machine starts from IDE
Only Generation 2 starts from
SCSI
Cannot modify devices while
virtual machine is running
Can modify devices when
virtual machine is running
• Fixed size, dynamically expanding or differencing disk files
• Directly attached disks—local, or on iSCSI or Fibre Channel
SAN
Overview of the Hyper-V Virtual Hard Disk Formats
• .vhd
• Up to 2,048 GB in size
• .vhdx
• Up to 64 TB in size
• Internal log for enhanced resiliency
• User defined metadata
• Large disk sector support
• Larger sector size (improved performance)
• Default format in Windows Server 2012 R2
• Can convert between both formats
• .vhdx recommended, if not used on older versions of
Hyper-V
Fixed Size and Dynamically Expanding Virtual Hard
Disks
Fixed size
Dynamically expanding
Allocates all storage
• Larger initial size
• Creation takes time
(without Windows
Offloaded Data
Transfers)
Allocates space as needed
• Smaller initial size
• Created faster
Minimize fragmentation
Can cause fragmentation
Cannot over-commit
Can over-commit
Better performance (older
Hyper-V)
Comparable performance
(Windows Server 2012)
Use in production
Use in testing and
development
Differencing Virtual Hard Disks
• Stores changes from the parent disk
•
•
•
•
Parent disk should not change
Differencing disk isolate changes
Multiple differencing disks can use same parent
Increases overhead (lower performance)
• Can be used for standardized base images
• Should avoid in production
Create
Read
Modify
Delete
3
1234
123 4
File A
File B
1 23 4
File
C
xxxx
12 34
File D
Grow
Read-Only
Directly Attached Storage
• Virtual machine directly accesses physical disk
• Internal or LUN attached to Hyper-V server
•
•
Disk must be offline before it can be used
LUN on iSCSI or Fibre Channel SAN
• Pass-through disk considerations
• Best performance
• Unlimited size, lowest CPU utilization
• No checkpoints or differencing virtual hard disks
• No portability and encapsulation
• Not included in Hyper-V backup
Virtual Hard Disk Sharing and Quality of Service
Management
• Provides shared storage for virtual machines
• Used as shared SAS disk by virtual machines
• Virtual hard disk must be using VHDX format
•
•
Must be connected to virtual SCSI controller
Must be stored on failover cluster
• CSV
• Scale-out file server with SMB 3.0
•
Separation between infrastructure and virtual machines
• Storage QoS restrict disk throughput
• Configured per virtual hard disk
• Dynamically configurable while virtual machine is
running
Hyper-V Considerations for Virtual Hard Disk Storage
• Virtual hard disks consume large amounts of
space
•
Can increase over time, implement monitoring
• Use multiple physical disks for better throughput
• Use redundant storage spaces
• SSD dramatically increases performance
• SMB 3.0 file share
• Use SAN for storing virtual hard disks
• Specialized, redundant, fast
• Shared storage for failover clustering
• Exclude VHDs from antivirus scanning
Lesson 2: Creating and Configuring Virtual Machines
• What Are the Components of a Generation 1 Virtual Machine?
• Overview of Generation 2 Virtual Machines
• Configuring Virtual Machine Settings
• What Is Dynamic Memory?
• What Is Smart Paging?
• Overview of Integration Services
• Using a Virtual Fibre Channel Adapter
What Are the Components of a Generation 1 Virtual Machine?
• Virtual machine has virtual hardware devices
• Only devices that Hyper-V supports can be used
• Virtual hardware can be:
• Emulated – available during boot
• Synthetic – available in supported operating systems
• SR-IOV – available in supported operating systems
• Prior to Windows Server 2012 R2, only Generation 1
virtual machines were available
Overview of Generation 2 Virtual Machines
• Emulated devices are removed
• UEFI firmware instead of BIOS
• Secure boot
• Boots from SCSI controller
• PXE boot uses a standard network adapter
• Faster boot and operating system installation
• Can run side by side with Generation 1
• Generation 1 must be used for legacy systems
• Supported guest operating systems
• Windows Server 2012 and Windows Server 2012 R2
• 64-bit versions of Windows 8 and Windows 8.1
Configuring Virtual Machine Settings
• Only limited options are available during creation
Many more options are available after the virtual machine is
created
• Configuration options depend on the generation of the virtual
machine
•
• Most settings can be configured only if turned off
Adding or removing hardware components
• Configuring memory, processor, disk settings
• Few settings are configurable while virtual machine is running
•
•
•
•
Connecting a network adapter to a virtual switch
Adding a virtual hard disk to a SCSI controller
Enable or disable Integration Services
• Use Hyper-V Manager or Windows PowerShell
• Set-VM, Add-VMHardDiskDrive, Add-VMNetworkAdapter
What Is Dynamic Memory?
• More efficient use of available physical memory
•
Shared resource that can be reallocated automatically
•
Demand, available memory, and virtual machine memory settings
• Dynamic memory settings
•
Startup RAM
•
•
Minimum RAM
•
•
Can be increased while virtual machine is running
Memory buffer
•
•
Can be decreased while virtual machine is running
Maximum RAM
•
•
Operating system typically requires more memory when started
Percentage of extra memory to reserve for a virtual machine
Memory weight
•
Prioritizes memory allocation when physical memory is low
What Is Dynamic Memory?
Finance virtual machine
8 GB
Sales virtual machine
Engineering virtual machine
6 GB
4 GB
2 GB
T=0
T = 15
T = 30
Total System Memory
Memory in Use by virtual machines
Physical Memory Used
8 GB
3 GB
37.5 %
Virtual Machines
Memory Settings
What Is Dynamic Memory?
Finance virtual machine
8 GB
Sales virtual machine
Engineering virtual machine
6 GB
4 GB
2 GB
T=0
T = 15
T = 30
Total System Memory
Memory in Use by virtual machines
8 GB
6 GB
Physical Memory Used
75 %
Virtual Machines
Memory Settings
What Is Dynamic Memory?
Finance virtual machine
8 GB
Sales virtual machine
Engineering virtual machine
Service virtual machine
6 GB
Engineering reaches
max allocation
4 GB
2 GB
T=0
T = 15
T = 30
Total System Memory
Memory in Use by virtual machines
Physical Memory Used
8 GB
7,5 GB
94 %
Virtual Machines
Memory Settings
What Is Smart Paging?
• Memory Management technique that uses
physical disk resources as temporary memory
Ensures that a virtual machine can always restart
• Used during virtual machine restart only
•
•
•
•
•
Temporarily degrades virtual machine performance
•
•
If Hyper-V is low on memory, and
The virtual machine has more startup than minimum RAM, and
Memory cannot be reclaimed from other virtual machines
Used only for a limited time, and then removed
Not used when a virtual machine started from the Off
state
•
Virtual machine operating system paging is always preferred
What Is Smart Paging?
Finance virtual machine
Sales virtual machine
Engineering virtual machine
Service virtual machine
8 GB
Virtual Machines
Memory Settings
6 GB
4 GB
2 GB
T=0
T = 15
Total System Memory
T = 30
8 GB
• Sales virtual machine and Service virtual
machine can be restarted only if Smart Paging is
used
Overview of Integration Services
• Makes a guest operating system aware that it is running
on a virtual machine
• Many operating systems include integration services
Install the latest integration services
• VMBus and synthetic devices support
• Time synchronization, mouse release, VSS
•
• Managed as virtual machine settings
Overview of Integration Services
Without Integration Services
With Integration Services
Using a Virtual Fibre Channel Adapter
• Access to Fibre Channel SAN storage from virtual machine
Hyper-V server has Fibre Channel HBA
• Use Virtual SAN Manager to configure a virtual SAN
•
•
•
Virtual Fibre Channel adapter maps to the physical HBAs
Virtual Fibre Channel adapter connects to the Virtual SAN
• Storage hardware must support N_Port ID virtualization
• Virtual machine can have four virtual Fibre Channel
adapters
Supported
Not supported
Virtual machine live migration
Boot from Fibre Channel SAN
Virtual machine failover cluster
Checkpoints
MPIO - multiple paths to SAN
Host-based backup
Live migration of SAN data
Lesson 3: Installing and Importing Virtual Machines
• Virtual Machine Installation Methods
• Importing Virtual Machines
• Virtualizing a Physical Computer
• The Virtual Machine Connection Application
• Overview of Enhanced Session Mode
Virtual Machine Installation Methods
• Install from a bootable CD/DVD-ROM
•
Single virtual machine can only use physical media at one time
• Install from an .iso file
•
Multiple virtual machines can use .iso file
• Install from a network-based installation server
•
Generation 1 – legacy network adapter required
• Copy virtual hard disk file with operating system
installed
Similar to computer cloning
• Virtual hard disk should first be generalized
•
• Use differencing virtual hard disks
Parent virtual hard disk should first be generalized
• Parent virtual hard disk must not change
•
Importing Virtual Machines
• You can import a virtual machine without first exporting it
Only virtual machine data files are needed
• Over 40 different types of issues detected, such as:
•
•
•
•
Missing parent virtual hard disk
Virtual switch not available
Virtual machine has more processors than available
• Import process:
•
•
•
•
•
Creates a copy of the virtual machine configuration file
Validates hardware configuration settings
Compiles a list of incompatibilities
Displays incompatibilities and asks for new settings
Removes the configuration file copy
• Cannot start older saved states and checkpoints
Virtualizing a Physical Computer
• Converting a physical computer to a virtual machine
• Hyper-V does not include P2V functionality
• Hyper-V can copy content of data disks
• Configure disk in New Virtual Hard Disk Wizard
• Copy entire disk, not volume or partition
• Supported only for data, system disks are not supported
• Disk2vhd
• Creates virtual hard disks
• Uses VSS
• Captured system has same identity
• Add virtual hard disk to virtual machine
Virtualizing a Physical Computer
The Virtual Machine Connection Application
• Connects to virtual machines on local and remote
Hyper-V
Port 2179 used (can be modified in the registry)
• Connection allowed by Windows Firewall
• Installed as part of Hyper-V role or RSAT feature
•
•
Single users can connect to virtual machines
•
Remote Desktop in virtual machines is not used
• Hyper-V Administrators can connect to virtual
machines
You can restrict access to virtual machines
• Revoke-VMConnectAccess cmdlet
•
Overview of Enhanced Session Mode
• Remote Desktop connection to a virtual machine
• Virtual machine can be without network connectivity
• Devices can be redirected
•
•
•
•
Printers, drives, smart cards, audio, other PnP devices
Shared clipboard, enhanced copy
Folder redirection
RDS component is used
•
•
User must sign in to virtual machine
Remote Desktop Users group membership required
• Enabled at Hyper-V virtual machine connection and
virtual machine level
• Guest operating system support required
Windows Server 2012 R2 or Windows 8.1
• Available only when the virtual machine is running
•
Lesson 4: Managing Virtual Machine Checkpoints
• What Are Virtual Machine Checkpoints?
• Implementing Hyper-V Checkpoints
• Overview of Checkpoints at File Level
• Exporting Virtual Machines and Checkpoints
• Issues with Checkpoints in Distributed Environments
• Checkpoints and Virtual Machine Generation ID
What Are Virtual Machine Checkpoints?
• Checkpoint is a point-in-time virtual machine state
•
•
•
Can be taken if virtual machine is not in Paused state
Contains virtual machine configuration, memory and disk state
Does not affect the running state of a virtual machine
• Primarily used for testing and development
•
•
•
Can cause issues in distributed production environment
Create differencing disk – decrease performance
• Cannot be created for directly attached disks
Used by Hyper-V Replica or in VDI deployments
Implementing Hyper-V Checkpoints
• When created, a checkpoint cannot be modified
• Only viewed, applied, exported, renamed, or deleted
• Checkpoint creation steps:
1.
2.
3.
4.
5.
Pause virtual machine
Create differencing disk for each disk that virtual machine is using
Create a copy of virtual machine configuration
Resume virtual machine
Copy virtual machine memory to disk
• Checkpoint consists of
• Configuration file (*.xml)
• Saved state file (*.vsv)
• Memory content (*.bin)
• Differencing disks (*.avhd)
Overview of Checkpoints at File Level
Snapshot
.vhd
.avhd
Apply (create branch)
Apply (= delete Now)
Delete (= merge)
Delete (= delete)
Exporting Virtual Machines and Checkpoints
• Exporting a virtual machine is not required
•
You can copy virtual machine files
• Exporting virtual machine consolidate its files
•
If differencing drives are used, the entire hierarchy is exported
•
•
Exporting multiple virtual machines increases total size
When exporting a virtual machine, all its checkpoints are exported
• Exporting a checkpoint exports only a single state
•
Differencing disks in checkpoint hierarchy are merged
• Live export – you can export while a virtual machine is
running
• Update integration services after import
•
Discard memory content and saved state from different
architecture or pre-Windows 2012 Hyper-V
Issues with Checkpoints in Distributed Environments
• Applying a checkpoint takes a virtual machine back to a
previous state
• Can have serious implications and result in corruption
•
Vector-clock synchronizations are impacted
•
Distributed applications depending on increasing logical clock
• AD DS, DFS Replication, SQL Server replication
•
•
Applying checkpoint rolls back the logical clock
Members of replica set to not converge to the same state
Cryptography - reducing entropy of the random data
• Distributed applications using vector clock algorithms have
no awareness of running in a virtual environment
• Removes changes in virtual machine as if they never
happened
•
•
User data is lost, passwords are reverted
• Regardless of whether they were already synchronized or replicated
Issues with Checkpoints in Distributed Environments
DC2
DC1
T1
Create
Checkpoint
USN: 100
ID: A
RID Pool: 500 - 1000
Time
+100
users
Only
50
T2
T3
users are replicated to both domain
controllers. Others are either on first or second
USN: 200
domain controller. 100 users (RID 500-599) have
ID: A
Replication to DC2: USN >100
RID Pool: 600 - 1000
duplicated SIDs.
Apply T1
Checkpoint
DC1(A)
@USN =
200
USN: 100
ID: A
RID Pool: 500 - 1000
+150 users
USN: 250
T4
ID: A
RID Pool: 650 - 1000
Replication to DC2: USNs >200
DC1(A)
@USN =
250
Checkpoints and Virtual Machine Generation ID
• Designed to address issues of reverting to a past state
64-bit integer, tied to a virtual machine configuration
• Generation ID passed to a virtual machine in the BIOS
•
•
•
Application can compare current and previous values
If values differ, then something happened to virtual machine
• Hypervisor must support virtual machine generation ID
• Operating system in virtual machine must be
generation ID-aware
Virtual machine generation ID change
Does not change
Virtual machine starts from checkpoint
Virtual machine is live-migrated
Virtual machine restored from backup
Virtual machine is paused or
resumed
Virtual machine is migrated
Virtual machine is restarted
Virtual machine is imported
Hyper-V server is restarted
Checkpoints and Virtual Machine Generation ID
Checkpoints and Virtual Machine Generation ID
Checkpoints and Virtual Machine Generation ID
Lesson 5: Monitoring Hyper-V
• Overview of Performance Monitoring
• Monitoring a Hyper-V Host
• Monitoring Virtual Machines
• Resource Metering in Hyper-V
Overview of Performance Monitoring
• Monitors operating system and applications using
system resources
• Provides up-to-date information on performance
•
Health of the IT infrastructure
•
•
Planning for future requirements
•
•
Compare current activity with the baseline
Whether current performance is sufficient
Identifying issues
•
•
Detecting problems
Proactive (real-time) and reactive (historical data)
• Windows Server 2012 R2 includes several tools
• Operations Manager centralizes monitoring,
alerting, and reporting for the enterprise
Overview of Performance Monitoring
Task Manager provides local, real-time performance data
• Helps to identify and resolve performance-related issues
Overview of Performance Monitoring
Resource Monitor provides in-depth real-time performance
data
• CPU, Memory, Disk, Network
Overview of Performance Monitoring
Event Viewer shows events that relate to server activity
• Collected locally and remotely
• Filtering, custom views, attaching tasks to the events
Overview of Performance Monitoring
Reliability Monitor provides an historical view of server
reliability and associated events
Overview of Performance Monitoring
Performance Monitor provides real-time monitoring and
viewing of historical data gathered by data collector sets
•
Additional performance objects added with server roles
Monitoring a Hyper-V Host
• Only Performance Monitor can monitor Hyper-V
• Many Hyper-V performance objects added
• Other tools monitor only their virtual environment
•
Parent partition is also considered a virtual machine
• Memory, disk and network monitored the same
• \Logical Disk(*)\Avg. Disk sec/Read and /Write
• \Memory\Available Mbytes
• \Network Interface(*)\Bytes Total/sec
• Processor utilization based on available resources
• Hyper-V allocates resources to each virtual machine
• \Processor(*)\% Processor Time shows relative utilization
• \Hyper-V Hypervisor Logical Processor(_Total)\% Total
Run Time should be used
Monitoring Virtual Machines
• Virtual machine tools monitor the virtual environment
Heavy utilization in virtual machine does not mean that
Hyper-V host is heavy utilized (and vice versa)
• Available resources adjusted based on server load
•
• Memory and disk counters are the same as on the server
• Hyper-V performance counters should be used
Hyper-V Hypervisor\Virtual Processors
• Hyper-V Hypervisor Logical Processor \% Guest Run Time
• Hyper-V Virtual Network Adapter(*)\Bytes/sec
•
• Limit the processor resources that the virtual machine can
use
Resource Metering in Hyper-V
• Track resources used by virtual machine or pool
• Processor, disk, memory, network
• Can be used for charge back
• Resource metering data follows a virtual machine
• Configure by using Windows PowerShell
• Enable-VMResourceMetering, Measure-VM
•
•
•
•
•
Average CPU usage
Average physical memory usage
Minimum/maximum memory usage
Maximum amount of disk space allocated to a virtual machine
Total incoming/outgoing network traffic for a network adapter
• Graphical reporting is not included
• Basic reporting in Windows PowerShell