|
Measures reported by RHEVMgrNetTest
Logical networking allows the Red Hat Enterprise Virtualization environment to separate network traffic by type. For example, the rhevm network is created by default during the installation of the Red Hat Enterprise Virtualization to be used for management communication between the Manager and hosts. A typical use for logical networks is to group network traffic with similar requirements and usage together. In many cases, a storage network and a display network are created by an administrator to isolate traffic of each respective type for optimization and troubleshooting.
Logical networks are defined at the data center level, and added to a host. For a logical network to be operational, it must be implemented for every host in a given cluster. Each logical network in a Red Hat Enterprise Virtualization environment is backed by a network bridge device on a host. So when a new logical network is defined for a cluster, a matching bridge device must be created on each host in the cluster before the logical network can become operational to be used by virtual machines. Red Hat Enterprise Virtualization Manager automatically creates required bridges when a host has been put into maintenance mode.
The network bridge device that is created by the Red Hat Enterprise Virtualization Manager to back a logical network device is associated with a physical network device. If the physical NIC that a bridge includes has network connectivity, then any network interfaces that are subsequently included in the bridge share the network connectivity of the bridge. When virtual machines are created and placed on a particular logical network, their virtual network cards are included in the bridge for that logical network. Those virtual machines can then communicate with each other and with other objects that are connected to the bridge.
By continuously monitoring the status and usage of the logical networks, you can be instantly intimated when a logical network goes down, identify the clusters and hosts that are using each such logical network, and isolate those networks where traffic is high. The Logical Networks test does just that.
The measures
made by this test are as
follows:
| Measurement |
Description |
Measurement Unit |
Interpretation |
| Status |
Indicates the current status of this logical network.
|
|
This measure will report the value Up if the logical network is up and running currently, and Down if the logical network is currently inactive.
The numeric values that correspond to the Up/Down values above are as follows:
| Numeric Value |
Measure Value |
| 1 |
Up |
| 0 |
Down |
By default, this measure reports one of the Measure Values listed in the table above. The graph of this measure however will represent the Up/Down status using the numeric equivalents - ‘0’ or ‘1’. |
| Tot_clusters |
Indicates the number of clusters that are currently using this logical network. |
Number |
Both these measures are good indicators of the load on the logical networks. Use the detailed diagnosis of these measures to know which clusters and which RHEV servers are currently using a particular logical network. |
| Tot_hosts |
Indicates the number of RHEV hypervisors that are currently using this logical network during the last measurement period. |
Number |
| Tot_data_trans |
Indicates the rate at which data was transmitted over this logical network. |
Mbps |
By comparing the values of these measures across logical networks, you can quickly identify which logical network is generating the maximum network traffic. |
| Tot_data_rec |
Indicates the rate at which the data was received by this logical network.
|
Mbps |
Comparing the data received across all the hosts provides an indicator of the host that has the most in-bound network traffic. |
| Tot_err_trans |
Indicates the number of errors encountered by this logical network while sending data during the last measurement period.
|
Number |
Ideally, the value of these measures should be 0. Non-zero values indicate the occurrence of errors during transmission and/or reception of data. In this case, you can compare the value of each of these measures across the logical networks to isolate the error-prone logical networks. You can even compare the count of transmission errors with reception errors for every logical network to know when a large number of errors have occurred on that network - while transmitting data? or while receiving it? |
| Tot_err_recei |
Indicates the number of errors encountered by this logical network while receiving data during the last measurement period. |
Number |
| Tot_Datacent |
Indicates the number of data centers that are currently using this logical network. |
Number |
|
|