ESX Server Status in vCenter Test

This test reports the current state of each ESX server managed by vCenter. Disconnected hosts, hosts in the maintenance mode, and powered off hosts can be quickly identified using this test.

Target of the test : A VMware vCenter server

Agent deploying the test : An internal agent

Outputs of the test : One set of results for each vSphere/ESX host managed by the vCenter server being monitored.

Configurable parameters for the test
Parameter	Description
Test Period	How often should the test be executed.
Host	The host for which this test is to be configured.
Port	Refers to the port at which the specified host listens to.
VC User and VC Password	To connect to vCenter and extract metrics from it, this test should be configured with the name and password of a user with Administrator or Virtual Machine Administrator privileges to vCenter. However, if, owing to security constraints, you are not able to use the credentials of such users for test configuration, then you can configure this test with the credentials of a user with Read-only rights to vCenter. For this purpose, you can assign the ‘Read-only’ role to a local/domain user to vCenter, and then specify name and password of this user against the VC User and VC Password text boxes. The steps for assigning this role to a user on vCenter have been detailed in the Creating a Special Role on vCenter and Assigning the Role to a New User topic under the eG Monitoring Capabilities -> Virtualization and Containers -> Virtualization Technologies -> VMware vSphere ESX node sequence in the eG Enterprise documentation portal Monitoring VMware Infrastructures . vCenter servers terminate user sessions based on timeout periods. The default timeout period is 30 mins. When you stop an agent, sessions currently in use by the agent will remain open for this timeout period until vCenter times out the session. If the agent is restarted within the timeout period, it will open a new set of sessions. If you want the eG agent to close already existing sessions on vCenter before it opens new sessions, then, instead of the ‘Read-only’ user, you can optionally configure the VC User and VC Password parameters with the credentials of a user with permissions to View and Stop Sessions on vCenter. For this purpose, you can create a special role on vCenter, grant the View and Stop Sessions privilege (prior to vCenter 4.1, this was called the View and Terminate Sessions privilege) to this role, and then assign the new role to a local/domain user to vCenter. The steps for assigning this role to a user on vCenter have been detailed in the Creating a Special Role on vCenter and Assigning the Role to a New User topic under the eG Monitoring Capabilities -> Virtualization and Containers -> Virtualization Technologies -> VMware vSphere ESX node sequence in the eG Enterprise documentation portal Monitoring VMware Infrastructures .
Confirm Password	Confirm the password by retyping it in this text box.
SSL	By default, the vCenter server is SSL-enabled. Accordingly, the SSL flag is set to Yes by default. This indicates that the eG agent will communicate with the vCenter server via HTTPS by default.
Webport	By default, in most virtualized environments, vCenter listens on port 80 (if not SSL-enabeld) or on port 443 (if SSL-enabled) only. This implies that while monitoring vCenter, the eG agent, by default, connects to port 80 or 443, depending upon the SSL-enabled status of vCenter – i.e., if vCenter is not SSL-enabled (i.e., if the SSL flag above is set to No), then the eG agent connects to vCenter using port 80 by default, and if vCenter is SSL-enabled (i.e., if the ssl flag is set to Yes), then the agent-vCenter communication occurs via port 443 by default. Accordingly, the Webport parameter is set to default by default. In some environments however, the default ports 80 or 443 might not apply. In such a case, against the Webport parameter, you can specify the exact port at which vCenter in your environment listens, so that the eG agent communicates with that port for collecting metrics from vCenter.

Measurements made by the test

Measurement

Description

Measurement Unit

Interpretation

Connection status

Indicates the current connection state of this vSphere/ESX server.

The values this measure reports and their numeric equivalents are provided in the table below:

Measure Value	Numeric Value
Disconnected	0
Connected	1
NotResponding	2

Note:

Typically, this measure reports one of the Measure Values listed in the table above. In the graph of this measure however, the connection state of an ESX server is indicated by its corresponding numeric equivalent only - i.e., 0 to 2.

State of an active host in HA cluster

Indicates the current availability state of this host in an HA cluster.

In a vSphere HA cluster, the active hosts form a fault domain. A host is inactive if it is in standby or maintenance mode, or it has been disconnected from vCenter Server. A vSphere HA agent, called the Fault Domain Manager (FDM), runs on each host in the fault domain.

One FDM serves as the master and the remaining FDMs as its slaves. The master is responsible for monitoring the availability of the hosts and VMs in the cluster, and restarting any VMs that fail due to a host failure or non-user-initiated power offs. The master is also responsible for reporting fault-domain state to vCenter Server.

The master FDM is determined through election by the FDMs that are alive at the time. An election occurs in the following circumstances:

When the vSphere HA feature is enabled for the cluster.
When the master’s host fails.
When the management network is partitioned. In a network partition there will be a master for each partition. However, only one master will be responsible for a given VM. When the partition is resolved, all but one of the masters will abdicate.
After a host in a vSphere HA cluster powers back up following a failure that caused all hosts in the cluster to power off.

The slaves are responsible for reporting state updates to the master and restarting VMs as required.

The values that this measure reports and their numeric equivalents have been discussed in the table below

Measure Value	Numeric Value
Master	0
ConnectedToMaster	1
Election	2
Uninitialized	3
NetworkPartitioned FromMaster	4
FdmUnreachable	5
HostDown	6
NetworkIsolated	7
InitializationError	8
UnitializationError	9

Note:

Typically, this measure reports one of the Measure Values listed in the table above. In the graph of this measure however, the availability state of an ESX server in an HA cluster is indicated by its corresponding numeric equivalent only - i.e., 0 to 9.

Is in maintenance mode?

Indicates whether this host is currently in the maintenance mode or not.

If a vSphere host is in the maintenance mode, then VMware HA suspends failover operations during maintenance operations. In other words, when a host enters the maintenance mode, VMs are prevented from powering up or failing over to the host if that host is taking part in a high availability cluster.

The values this measure reports and their numeric equivalents are provided in the table below:

Measure Value	Numeric Value
Yes	1
No	0

Note:

Typically, this measure reports one of the Measure Values listed in the table above. In the graph of this measure however, the maintenance mode of an ESX server is indicated by its corresponding numeric equivalent only - i.e., 0 or 1.

Standby mode

Indicates whether this host is currently in the standby mode or not.

The VMware Distributed Power Management (DPM) feature allows a DRS cluster to reduce its power consumption by powering hosts on and off based on cluster resource utilization. VMware DPM monitors the cumulative demand of all virtual machines in the cluster for memory and CPU resources and compares this to the total available resource capacity of all hosts in the cluster. If sufficient excess capacity is found, VMware DPM migrates all the virtual machines on one/more hosts to other hosts and places such hosts in the standby mode (i.e., powers off the hosts). Conversely, when capacity is deemed to be inadequate, DRS brings hosts out of standby mode (powers them on) and migrates virtual machines, using VMotion, to them.

The values this measure reports and their numeric equivalents are provided in the table below:

Measure Value	Numeric Value
None	0
In	1
Entering	2
Exiting	3

Note:

Typically, this measure reports one of the Measure Values listed in the table above. In the graph of this measure however, the standby mode of an ESX server is indicated by its corresponding numeric equivalent only - i.e., 0 to 3.

Power state

Indicates whether this host is currently in the standby, powered off, or powered on mode.

The values this measure reports and their numeric equivalents are provided in the table below:

Measure Value	Numeric Value
Unknown	0
PoweredOn	1
PoweredOff	2
StandBy	3

Note:

Typically, this measure reports one of the Measure Values listed in the table above. In the graph of this measure however, the power state of an ESX server is indicated by its corresponding numeric equivalent only - i.e., 0 to 3.

Availability status

Indicates whether this host is currently in the maintenance, standby, powered on, or powered off modes.

The values this measure reports and their numeric equivalents are provided in the table below:

Measure Value	Numeric Value
In maintenance	0
PoweredOn	1
Unknown	2
PoweredOff	3
StandBy	4

Note:

Typically, this measure reports one of the Measure Values listed in the table above. In the graph of this measure however, the availability state of an ESX server is indicated by its corresponding numeric equivalent only - i.e., 0 to 4.

Is vSAN enabled?

Indicates whether/not the vSAN service is currently enabled for this host.

Virtual SAN virtualizes local physical storage resources of vSphere hosts and turns them into pools of storage that can be carved up and assigned to virtual machines and applications according to their quality of service requirements.

You can activate Virtual SAN when you create host clusters or enable Virtual SAN on existing clusters. When enabled, Virtual SAN aggregates all local storage disks available on the hosts into a single datastore shared by all hosts. You can later expand the datastore by adding storage devices or hosts to the cluster.

If a host contributes its local storage to the Virtual SAN datastore, the host must provide one SSD and at least one HDD, also called data disk. The disks on the contributing host form a disk group. Each disk group must include one SSD and at least one or multiple data disks. The disk group uses the SSD disk for read caching and write buffering, while the data disks are used for persistent storage. You can have multiple disk groups per host.

If vSAN is not enabled for a host, then the value of this measure will be No. If vSAN is enabled for a host, then the value of this measure will be Yes. The numeric values that correspond to these measure values are discussed in the table below:

Measure Value	Numeric Value
Yes	1
No	0

Note:

By default, this measure reports the Measure Values listed in the table above. In the graph of this measure however, the state of the vSAN is represented using the corresponding numeric equivalents only.