RHEV VM Details Test

This test monitors the amount of the physical server’s resources that each guest on an RHEV server is taking up. Using the metrics reported by this test, administrators can determine which virtual guest is taking up most CPU, which guest is generating the most network traffic, which guest is over-utilizing memory, etc. Note that the amount of resources taken up by a virtual guest will be limited by the resource allocations that have been made by administrators. For example, an administrator could cap the amount of memory that a specific guest may take.

Target of the Test: A RHEV Hypervisor

Agent running the test: A remote agent

Output of the test: One set of results for every VM on the RHEV hypervisor being monitored.

Configurable parameters for the test
Parameter Description

Test period

How often should the test be executed.

Host

The host for which the test is to be configured.

RHEL MGR Host,
RHEL MGR Port,
RHEL MGR Domain,
RHEL MGR User
RHEL MGR Password

To auto-discover the VMs on a target RHEV hypervisor and obtain the outside view of the performance of each VM, the eG agent needs to connect to the RHEV Manager that manages the target RHEV hypervisor. To enable the eG agent to obtain the outside view, you need to configure the test with the following:

  • RHEL MGR Host - The IP address/host name of the RHEV manager that the eG agent should connect to.
  • RHEL MGR Port - The port number at which the said RHEV manager listens.
  • RHEL MGR Domain - The domain to which the RHEV manager belongs.
  • RHEL MGR User and RHEL MGR Password - The credentials of a user with read-only access to the Restful API on the RHEV manager. To know how to create a read-only role and assign it to a user, follow the steps detailed in Configuring the eG Agent to use the RESTful APIs on the RHEV Manager to Obtain the “Outside View”.

If the RHEV hypervisor being monitored was discovered via an RHEV manager, then the IP address, port number, domain name, and user credentials of the RHEV manager used for discovery will be automatically displayed against the respective parameters.

If the RHEV hypervisor being monitored was not discovered via an RHEV manager, but you still want to use an RHEV manager for obtaining the outside view, then, you can select any IP address of your choice from the RHEL MGR host list. By default, this list will be populated with the IP addresses/host names of all the RHEV managers that were configured for the purpose of discovering the RHEV hypervisors. If you select an RHEL MGR host from this list, then the corresponding port number, domain name, and user credentials will be automatically displayed against the respective parameters.

On the other hand, if the RHEV manager that you want to use for metrics collection is not available in the RHEL MGR Host list, then, you can configure an RHEV manager on-the-fly by picking the Other option from the RHEL MGR Host list.  An ADD THE RHEV MANAGER DETAILS window will then pop up. Refer to Configuring an RHEV Manager to Use for Monitoring the RHEV Hypervisor to know how to add an RHEV manager using this window. Once the RHEV manager is added, its IP address, port number, domain name and user credentials will be displayed against the corresponding parameters.

Confirm Password

Confirm the RHEL MGR Password by retyping it here.

SSL

If the RHEV manager to which the eG agent should connect is SSL-enabled, then set this flag to Yes. If not, set it to No.

Hypervisor User

Specify the name of a user who has the right to connect to the RHEV hypervisor via SSH.

Hypervisor Password

Specify the password of the Hypervisor User.

Confirm Password

Confirm the Hypervisor Password by retyping it here.

Hypervisor SSH Port

Enter the SSH port at which the RHEV hypervisor listens.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

VM power state

Indicates whether this VM is currently powered-on or off.

 

This measure reports the value Up if the VM is currently powered-on, and the value Down if the VM is currently powered-off.

The numeric values that correspond to the measure values mentioned above are as follows:

Numeric Value Measure Value
1 Up
0 Down

Note:

By default, this measure reports the above-mentioned Measure Values while indicating the status of this VM. However, the graph of this measure powered-on states will be represented using the corresponding numeric equivalents only.

Is stateless VM?

Indicates whether this VM is currently stateless or not.

 

A stateless VM is not a VM that has its own local data. More often than not, it does require some local data or a local cache for better performance. But these data don’t need to be persisted. In some cases, a stateless VM can have additional software installed or data pulled in from a known repository. This process should be fully automated with self-starter scripts, or managed by an external installer.

Once a stateless VM goes live, it should discover all the related services to persistent data. The stateless VM has to rely on the environment to work effectively. It includes directory services, data services, and so on.

With stateless VMs, you can improve mobility inside an enterprise and external transfer to the public cloud. For one thing, you just need to transfer a VM image once and only once. When your application runs into problems, instead of diagnosing the problem you just remove the problematic VMs and add new virtual machines. With this capability, you can also easily scale out your applications by adding new VM instances as you need them.

Last but not least, the software upgrade and patch. It has been a big pain to upgrade and patch software in large deployments. You have to do it with each individual machine despite virtual or not. With stateless VM, you only need to patch the template and new virtual machines will pick it up seamlessly.

This measure reports the value Yes if the VM is a stateless VM, and the value No if it is not a stateless VM.

The numeric values that correspond to these measure values are discussed in the table below:

Numeric Value Measure Value
1 Yes
0 No

Note:

By default, this measure reports the above-mentioned Measure Values while indicating the VM is a stateless VM or not. However, in the graph of this measure this will be represented using the corresponding numeric equivalents only.

Number of VCPU

Indicates the number of virtual CPUs allocated to this VM.

Number

 

System usage of physical CPU

Indicates the percentage of physical CPU resources this VM utilized for system-level processing.

Percent

A high value could indicate that the VM is executing too many system-level tasks simultaneously.

Virtual CPU utilization

Indicates the percentage of virtual CPU resources this VM utilized.

Percent

Compare the value of this measure across VMs to identify the VM that is consuming CPU excessively. A high value for this measure could indicate that one/more CPU-intensive processes are executing on the VM.

Configured memory

Indicates the amount of memory that is allocated to this VM.

MB

 

Physical memory consumed

Indicates the amount of physical memory consumed by this VM.

MB

 

Memory usage

Indicates the percentage of physical memory consumed by this VM.

Percent

A high value for this measure is indicative of high memory usage by a VM. Compare the value of this measure across VMs to know which VMs are eroding the physical memory of the hypervisor. Once the resource-hungry  VMs are isolated, you need to investigate why those VMs are consuming memory excessively and see how the resource usage can be controlled. If the issue is allowed to persist, then very soon you may not have adequate physical memory to support hypervisor and VM operations.

Guaranteed memory

Indicates the amount of memory resources that is guaranteed available to this VM - i.e., the minimum amount of memory that will always be available to this VM.

MB

 

Disk status

Indicates the status of the virtual disk of this VM.

 

The value of this measure can be OK or Not ok, depending upon the current status of the disk.

The numeric values that correspond to these measure values are as follows:

Numeric Value Measure Value
1 Yes
0 No

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the status of the disk. However, in the graph of this measure, the disk status will be represented using the numeric equivalents of the measure values only.

Disk capacity

Indicates the current disk capacity of this VM.

GB

 

Data reads from disk

Indicates the rate at which data is read from the virtual disks of this VM.

MB/Sec

 

Data writes to disk

Indicates the rate at which data is written to the virtual disks of this VM.

MB/Sec

 

Disk throughput

Indicates the rate at which I/O operations are performed on the virtual disks of this VM.

MB/Sec

The value of this measure indicates the level of I/O activity on every VM. Compare this value across VMs to identify which VM is experiencing abnormally high disk I/O. Zooming into the internal operations of that VM can shed light on the I/O-intensive processes that may be executing in that VM.

Network data transmitted

Indicates the rate at which data is transmitted from this VM.

Mbps

 

Network data received

Indicates the rate at which data is received by this VM.

Mbps

 

Network throughput

Indicates the rate at which network data is accessed by this VM.

Mbps

For every VM, the value of this measure indicates the level of network traffic flowing into and from that VM. Compare this value across VMs to identify which VM is experiencing abnormally high traffic.