resource monitoring
DESCRIPTION
Resource Monitoring. Module 9. You Are Here. vSphere Environment. Operations. Introduction to VMware Virtualization. Access Control. VMware ESX and ESXi. Resource Monitoring. VMware vCenter Server. Data Protection. Networking. Scalability. Storage. High Availability. - PowerPoint PPT PresentationTRANSCRIPT
Resource Monitoring Module 9
Module 2-2
You Are Here
VMware vSphere 4.1: Install, Configure, Manage – Revision A
vSphere Environment
Introduction to VMware Virtualization
VMware ESX and ESXi
VMware vCenter Server
Networking
Storage
Virtual Machines
Operations
Access Control
Data Protection
Scalability
High Availability
Patch Management
Installing VMware ESX and ESXi
Resource Monitoring
Module 2-3
Importance
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Although the VMkernel works proactively to avoid resource contention, maximizing performance requires both analysis and ongoing monitoring.
Module 2-4
Module Lessons
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Lesson 1: Resource Controls and Resource Pools Lesson 2: Virtual CPU and Memory Concepts Lesson 3: Monitoring Resource Usage Lesson 4: Using Alarms
Module 2-5
Lesson 1:Resource Controls and Resource Pools
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-6
Lesson Objectives
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Describe resource allocation settings for: • CPU• Memory• Storage I/O
Create a resource pool
Module 2-7
Systems for Optimizing Virtual Machine Resource Use
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Managed by VMkernelConfigured by virtual machine owner
Adjustable by administrator
CPU cycles
• Hyperthreading• Load balancing• NUMA
• VMware® Virtual SMP
• Limit• Reservation• Share allocation
RAM
• Transparent page sharing
• vmmemctl• Memory compression• VMkernel swap files
for virtual machines
• Available memory
• Limit• Reservation• Share allocation
Disk bandwidth • Virtual machine
file location• Storage I/O Control• Multipathing
Network bandwidth
• NIC teaming
• Traffic shaping• Network I/O Control
(distributed virtual switch only)
Module 2-8
Resource Management
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Resource management is the allocation of resources from providers (hosts, clusters, and resource pools) to consumers (virtual machines). Resources include CPU, memory, storage, and network.
Resource management: Resolves resource overcommitment Prevents virtual machines from monopolizing resources Exploits undercommitted resources Controls the relative importance of virtual machines
Resource allocation settings: CPU and memory is controlled by using shares, limits, and reservations. Storage I/O is controlled by using shares and limits.
Module 2-9
Virtual Machine CPU Resource Settings
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Limit (MHz): A cap on the consumption
of CPU time by this virtual machine
Reservation (MHz): A certain number of CPU
cycles reserved for this virtual machine
Shares: A value that specifies the
relative priority or importance of a virtual machine
Module 2-10
How Virtual Machines Compete for Resources
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Proportional-share system for relative resource management: Applied during resource contention Prevents virtual machines from monopolizing resources Guarantees predictable resource shares
Number of shares
Change number of shares.
Power on VM.
Power off VM.
Module 2-11
Virtual Machine Memory Resource Settings
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Available memory: Memory size defined when the
virtual machine was createdLimit (MB): A cap on the consumption of
physical memory by this virtual machine
Reservation (MB): A certain amount of physical
memory reserved for this virtual machine
Shares: A value that specifies the relative
priority or importance of a virtual machine
A virtual machine swap file covers the range between available memory and reservation.
Module 2-12
Virtual Machine Storage I/O Resource Settings
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Storage I/O Control resource settings: Limit (IOPs):
• Cap on the storage I/O bandwidth for the virtual machine Shares:
• A value that shows relative importance of a virtual machine
Storage I/O Control: Must be enabled on the datastore Has several requirements
IOPS Iometer latencyVM1 1,500 20msVM2 1,500 21ms
IOPS Iometer latency1,080 31ms1,900 16ms
Example 1: Two VMs running Iometer(VM1:1,000 shares, VM2: 2,000 shares)
Without shares/limits With shares/limits
Module 2-13
What Is a Resource Pool?
VMware vSphere 4.1: Install, Configure, Manage – Revision A
A resource pool is a logical abstraction for hierarchically managing CPU and memory resources.It is used on standalone hosts or clusters enabled for VMware Distributed Resource Scheduler.It provides resources for virtual machines and child pools.
resource pools
rootresource
pool
Module 2-14
Why Use Resource Pools?
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Using resource pools can result in these benefits: Flexible hierarchical organization Isolation between pools and sharing within pools Access control and delegation Separation of resources from hardware Management of sets of virtual machines running a multitier
service
Module 2-15
Resource Pool Attributes
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Resource pool attributes: Shares:
• Low, Normal, High, Custom Reservations, in MHz and MB Limits, in MHz and MB:
• Unlimited access, by default (up to maximum amount of resource accessible)
Expandable reservation? • Yes – Virtual machines and subpools
can draw from this pool’s parent.• No – Virtual machines and subpools
can draw only from this pool, even if its parent has free resources.
Module 2-16
Resource Pool Scenario
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Company X’s IT department has two internal customers: The finance department supplies two-thirds of the budget. The engineering department supplies one-third of the budget.
Each internal customer has both production and test/dev virtual machines.We must cap the resource consumption of the test/dev virtual machines.
Module 2-17
Resource Pool Example
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-18
Resource Pools Example: CPU Shares
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-19
Resource Pools Example: CPU Contention
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-20
Expandable Reservation
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Borrowing resources occurs recursively from the ancestors of the current resource pool. Expandable Reservation option
must be enabled. This option offers more flexibility but
less protection.
Expanded reservations are not released until the virtual machine that caused the expansion is shut down or its reservation is reduced.
Retail pool
reservation: 3,000MHz expandable reservation: Yes
Root resource pool
total CPU: 10,200MHz
total memory: 3,000MB
eCommerce Apps pool
eCommerce Web pool
reservation:1,000MHz
expandable? No
reservation: 1,200MHz
expandable? Yes
An expandable reservation might allow a rogueapplication to claim all unreserved capacity.
Module 2-21
Example of Expandable Reservation (1)
VMware vSphere 4.1: Install, Configure, Manage – Revision A
eCommerce resource pools reserve 2,200MHz of the 3,000MHz that the Retail pool has reserved.Power on virtual machines in the eCommerce Web pool.With Expandable Reservation disabled on the eCommerce Web pool, VM3 cannot be started with a reservation of 500MHz. Lower the virtual machine
reservation. Enable Expandable Reservation. Increase the eCommerce Web
pool’s reservation.
Retail pool
reservation: 3,000MHz expandable reservation: No
VM1R=40
0
VM2R=30
0VM3
R=500
Root resource pool
Total CPU: 10,200MHz Total memory: 3,000 MB
eCommerce Apps pool
eCommerce Web pool
reservation:1,000MHz
expandable? No
reservation: 1,200MHz
expandable? Yes
Module 2-22
Example of Expandable Reservation (2)
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Enable Expandable Reservation on the eCommerce Web pool.The system considers the resources available in the child resource pool and its direct parent resource pool.The virtual machine’s reservation is charged against the reservation for eCommerce Web.eCommerce Web’s reservation is charged against the reservation for Retail.
Retail pool reservation: 3,000MHz
expandable reservation: Yes
Root resource pool
Total CPU: 10,000MHz Total memory: 3,000MB
VM4R=500
VM5R=500
VM6R=500
VM1R=400
VM2
R=300
VM7R=500
VM3R=500
**200MHz used by Retail**
**full reservation used**
eCommerce Apps pool
eCommerce Web pool
reservation:1,000MHz
expandable? Yes
reservation: 1,200MHz
expandable? Yes
Module 2-23
Admission Control for CPU and Memory Reservations
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Power on a virtual machine. Create a new subpoolwith its own reservation.
Increase a pool’sreservation.
Expandablereservation?
Can this poolsatisfy reservation?
No
Yes – Go to parent pool.
Succeed
FailNo
Yes
Module 2-24
Resource Pool Summary Tab
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Click the resource pool’s Summary tab in the Hosts and Clusters inventory view.
Module 2-25
Resource Allocation Tab
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Click the resource pool’s Resource Allocation tab.
Module 2-26
Scheduling Changes to Resource Settings
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Schedule a task to change the resource settings of a resource
pool or a virtual machine.
Module 2-27
Lab 14
VMware vSphere 4.1: Install, Configure, Manage – Revision A
In this lab, you will create and use resource pools on an ESXi host.1. Create a resource pool.2. Verify resource pool functionality.
Module 2-28
Lesson Summary
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Describe resource allocation settings for:• CPU• Memory• Storage I/O
Create a resource pool
Module 2-29
Lesson 2:Virtual CPU and Memory Concepts
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-30
Lesson Objectives
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Identify the methods used by the VMkernel for optimizing CPU and memory usage
Module 2-31
Multicore Processors
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-32
Hyperthreading
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Hyperthreading enables a core to execute two threads, or sets of instructions, at the same time.To enable hyperthreading:
1. Verify that system supports hyperthreading.
2. Enable hyperthreading in the system BIOS.
3. Ensure that hyperthreading for the VMware ESX™/ESXi host is turned on.
Module 2-33
CPU Load Balancing
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-34
Memory Virtualization Overview
VMware vSphere 4.1: Install, Configure, Manage – Revision A
The VMkernel manages a machine’s entire memory. Part of this memory is used by the VMkernel. Some memory is used by the service console (ESX only). The rest is available for use by virtual machines:
• Configured memory, plus overhead
Virtual machines can use more memory than the physical machine has available. This is called memory overcommitment.
Memory compression improves virtual machine performance when memory is overcommitted. When memory becomes overcommitted, virtual pages are
compressed and stored in memory. Compressed memory is faster to access than memory swapped
to disk.
Module 2-35
Transparent Page Sharing
VMware vSphere 4.1: Install, Configure, Manage – Revision A
The VMkernel detects identical pages in the memory of virtual machines and maps them to the same underlying physical page: No changes to guest
operating system requiredThe VMkernel treats the shared pages as copy-on-write: Read-only when shared Private copies after write
A best practice is to always keep transparent page sharing enabled.
hardware RAM
VM RAMVM RAMVM RAM
Module 2-36
vmmemctl: Balloon-Driver Mechanism
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Deallocate memory from selected virtual machines when RAM is scarce.
Inflate balloon. (Driver demands
memory from guest OS.)
Guest is forced to page out to its own paging area.
The VMkernel reclaims memory.
Guest can page in. ESX/ESXi
grants memory.
Deflate balloon. (Driver relinquishes
memory.)
Ample memory.Balloon remains
uninflated.
Module 2-37
VMkernel Swap
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Each powered-on virtual machine needs its own VMkernel swap file: Created when the virtual machine is
powered on. Deleted when the virtual machine is powered off.
Default location: same VMware vStorage VMFS volume as virtual machine’s boot disk.
Size is equal to the difference between the memory guaranteed to it, if any, and the maximum it can use.
Allows the VMkernel to swap out the virtual machine entirely if memory is scarce.
Use of VMkernel swap is a last resort. Performance will be noticeably slow.
Module 2-38
Ballooning Compared with VMkernel Swapping
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-39
Lesson Summary
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Identify the methods used by the VMkernel for optimizing CPU and memory usage
Module 2-40
Lesson 3:Monitoring Resource Usage
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-41
Lesson Objectives
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Monitor a virtual machine’s resource usage:• CPU• Memory• Disk• Network bandwidth
Module 2-42
Performance-Tuning Methodology
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Assess performance. Use appropriate
monitoring tools. Record a numerical
benchmark before changes.
Identify the limiting resource.Make more resources available. Allocate more. Reduce competition. Log your changes.
Benchmark again.
Do not make casual changes to production systems.
Module 2-43
Guest Operating System Monitoring Tools
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Task ManagerIometer
Module 2-44
Using Perfmon to Monitor Virtual Machine Resources
VMware vSphere 4.1: Install, Configure, Manage – Revision A
The Perfmon DLL in VMware Tools provides virtual machine processor and memory objects to access host statistics
inside a virtual machine.
Module 2-45
VMware vCenter Server Performance Charts
VMware vSphere 4.1: Install, Configure, Manage – Revision A
The Performance tab displays two kinds of charts for hosts and virtual machines: Overview charts:
• Display the most common metrics for an object
Advanced charts:• Display data counters
not shown in the overview charts
Module 2-46
Interpreting Data from the Tools
VMware vSphere 4.1: Install, Configure, Manage – Revision A
VMware vCenter™ Server monitoring tools and guest operating system monitoring tools provide different points of view.
Task Manager inguest operating system
CPU Usagechart for host
Module 2-47
Is a Virtual Machine CPU-Constrained?
VMware vSphere 4.1: Install, Configure, Manage – Revision A
If CPU usage is continuously high, the virtual machine is constrained by CPU.But the host might have enough CPU for other virtual machines to run.
Check the virtual machine’s CPU
usage.
Module 2-48
Are Virtual Machines CPU-Constrained?
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Multiple virtual machines are constrained by CPU if: There is high CPU use in the guest operating system There are relatively high CPU ready values for the virtual machines
CPU Ready graph of several virtual machinesTask Manager of several operating systems
Module 2-49
Is a Virtual Machine Memory-Constrained?
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Check the virtual machine’s ballooning activity: If ballooning activity is high, this might not be a problem if all virtual
machines have sufficient memory. If ballooning activity is high and the guest operating system is swapping,
then the virtual machine is constrained for memory.
Module 2-50
Is the Host Memory-Constrained?
VMware vSphere 4.1: Install, Configure, Manage – Revision A
If there is active host-level swapping, then host memory is overcommitted.
Module 2-51
Monitoring Active Memory of a Virtual Machine
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Monitor for increases in active memory on the host: Host active memory refers to active physical memory used by virtual
machines and the VMkernel. If amount of active memory is high, this could lead to virtual machines
that are memory-constrained.
Module 2-52
Are Virtual Machines Disk-Constrained?
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Disk-intensive applications can saturate the storage or the path.If you suspect that a virtual machine is constrained by disk access: Measure the throughput and latency between the virtual machine
and storage. Use the advanced performance charts to monitor:
• Read rate and write rate • Read latency and write latency
Inventory object Chart option Storage typeHost Datastore FC, iSCSI, NFSHost Storage adapter FCHost Storage path FC, iSCSI
Virtual machine Datastore FC, iSCSI, NFSVirtual machine Virtual disk FC, iSCSI, NFS
Module 2-53
Monitoring Disk Latency
VMware vSphere 4.1: Install, Configure, Manage – Revision A
To determine disk performance problems, monitor two disk latency data counters: Kernel command latency:
• The average time spent in the VMkernel per SCSI command.• High numbers (greater than 2–3ms) represent either an overworked
array or an overworked host. Physical device command latency:
• The average time the physical device takes to complete a SCSI command.
• High numbers (greater than 15–20ms) represent a slow or overworked array.
Module 2-54
Are Virtual Machines Network-Constrained?
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Network-intensive applications often bottleneck on path segments outside the ESX/ESXi host: Example: WAN links between server and client
If you suspect that a virtual machine is constrained by the network: Confirm that VMware Tools is installed.
• Enhanced network drivers are available. Measure the effective bandwidth between the virtual machine
and its peer system. Check for dropped receive packets and dropped transmit
packets.
Module 2-55
Lab 15
VMware vSphere 4.1: Install, Configure, Manage – Revision A
In this lab, you will see how CPU workload is reflected by system monitoring tools.1. Use vCenter Server to monitor CPU utilization.
Module 2-56
Lesson Summary
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Monitor a virtual machine’s resource usage:• CPU• Memory• Disk• Network bandwidth
Module 2-57
Lesson 4:Using Alarms
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Module 2-58
Lesson Objectives
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Create alarms with condition-based triggers Create alarms with event-based triggers View and acknowledge triggered alarms
Module 2-59
What Is an Alarm?
VMware vSphere 4.1: Install, Configure, Manage – Revision A
An alarm is a notification that occurs in response to selected events or conditions that occur with an object in the inventory.Default alarms exist for various inventory objects: Many default alarms for hosts
and virtual machines
You can create custom alarms for a wide range of inventory objects: Virtual machines, hosts,
clusters, datacenters, datastores, networks, distributed switches, and distributed port groups
Default datacenter
alarms (partial list)
Module 2-60
Alarm Settings
VMware vSphere 4.1: Install, Configure, Manage – Revision A
To create an alarm, right-click the inventory object and select Alarm > Add Alarm.
Alarm types for:Virtual machines
HostsClusters
DatacentersDatastoresNetworks
Distributed switchesDistributed virtual port groups
Module 2-61
Alarm Triggers
VMware vSphere 4.1: Install, Configure, Manage – Revision A
An alarm requires a trigger. Types of triggers: Condition or state trigger – Monitors the current condition
or state. Example:• A virtual machine’s current snapshot is above 2GB in size.• A host is using 90 percent of its total memory.• A datastore has been disconnected from all hosts.
Event – Monitors events. Example:• The health of a host’s hardware has changed.• A license has expired in the datacenter.• A host has left the vNetwork distributed switch.
Module 2-62
Configuring Condition Triggers
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Condition triggers for a virtual machine
Module 2-63
Configuring Event Triggers
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Event trigger for a host
Module 2-64
Configuring Reporting Options
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Use the Reporting pane to avoid needless re-alarms.
Avoid small
fluctuations.
Avoid repeats.
Module 2-65
Configuring Actions
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Every alarm type has these actions: Send a notification email, send a notification trap, or run a command.
Virtual machine alarms and host alarms have more actions.
Module 2-66
Configuring vCenter Server Notifications
VMware vSphere 4.1: Install, Configure, Manage – Revision A
In the menu bar, select Administration > vCenter Server Settings.
Select SNMP to specify trap
destinations.
Select Mail to set SMTP parameters.
Module 2-67
Viewing and Acknowledging Triggered Alarms
VMware vSphere 4.1: Install, Configure, Manage – Revision A
The Acknowledge Alarm feature is used to track when triggered alarms are addressed.
Module 2-68
Lab 16
VMware vSphere 4.1: Install, Configure, Manage – Revision A
In this lab, you will demonstrate the vCenter Server alarm feature.1. Create a virtual machine alarm that monitors for a condition.2. Create a virtual machine alarm that monitors for an event.3. Trigger virtual machine alarms and acknowledge them.4. Disable virtual machine alarms.
Module 2-69
Lesson Summary
VMware vSphere 4.1: Install, Configure, Manage – Revision A
Create alarms with condition-based triggers Create alarms with event-based triggers View and acknowledge triggered alarms
Module 2-70
Key Points
VMware vSphere 4.1: Install, Configure, Manage – Revision A
The VMkernel has built-in mechanisms (such as CPU load balancing and transparent page sharing) for managing the CPU and memory allocation on an ESX/ESXi host.
The Performance tab allows you to monitor a host or virtual machine’s performance in real time or over a period of time.
Use alarms to monitor your vCenter Server inventory. Alarms notify you when selected events or conditions have occurred.