vSAN Physical DiskTest
This test auto-discovers the physical disks in the vSAN cluster and reports the type and current health of each disk. This helps administrators to instantly identify the unhealthy disks and proactively treat the unhealthy disks to prevent prolonged delays in data access for users. This test also reveals the capacity and utilization of each disk, using which any abnormalities can be detected before users start complaining of slowdowns and reduced performance of the cluster. In the process, this test also measures the throughput of read and write operations performed on physical and vSAN layers of each disk. The measured throughput values help administrators to easily find out how well/badly the read and write operations are performed on the physical disks. In addition, the time taken to perform the read and write operations on each disk is also revealed. Using this revelation, administrators can identify the disk which experienced delay while processing the IO operations.
Note:
This test is applicable only for the vSAN enabled clusters in the VMware vCenter server.
Target of the test : A VMware vCenter server
Agent deploying the test : An internal agent
Outputs of the test : One set of results for VMware vCenter server that is being monitored.
Parameter | Description |
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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 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 |
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. |
DD Frequency |
Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 1:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD frequency. |
Detailed Diagnosis |
To make diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option. The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:
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Measurement | Description | Measurement Unit | Interpretation | ||||||||||||||||||||
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Drive type |
Indicates the drive type of this physical disk. |
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The values this measure reports and their numeric equivalents are provided in the table below:
Note: Typically, this measure reports one of the Measure Values listed in the table above. In the graph of this measure however, the drive type of an physical disk is indicated by its corresponding numeric equivalents only. |
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Health |
Indicates the current health of this physical disk. |
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The values this measure reports and their numeric equivalents are provided in the table below:
Note: Typically, this measure reports one of the Measure Values listed in the table above. In the graph of this measure however, the health of an physical disk is indicated by its corresponding numeric equivalents only. |
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Capacity |
Indicates the total capacity of this disk. |
GB |
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Used capacity |
Indicates the amount of space utilized on this disk. |
GB |
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Used utilization |
Indicates the percentage of space utilized on this disk. |
Percentage |
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Reserved capacity |
Indicates the amount of space that is reserved on this disk for Thick Provisioning. |
GB |
Some of the objects on vSAN datastore are assigned a storage policy with an Object Space Reservation (OSR) rule set to Thick Provisioning. vSAN reserves the amount of configured capacity for objects with OSR. The capacity is commonly used for an important workload that dynamically consumes storage capacity. |
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Reserved utilization |
Indicates the percentage of space that is reserved on this disk for Thick Provisioning. |
Percentage |
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Physical layer read IOPS |
Indicates the number of read IO operations performed on the Physical layer of this disk. |
IOPS |
Compare the value of this measure across disks to know which disk handled the maximum number of read requests and which handled the least. If the gap between the two is very high, then it indicates serious irregularities in load-balancing across disks. |
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Physical layer write IOPS |
Indicates the number of write IO operations performed on the Physical layer of this disk. |
IOPS |
Compare the value of this measure across disks to know which disk handled the maximum number of write requests and which handled the least. If the gap between the two is very high, then it indicates serious irregularities in load-balancing across disks. |
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Physical layer read throughput |
Indicates the rate at which the data was read from the Physical layer of this disk. |
MB/sec |
A high value is desired for this measure. A very low value is a cause for concern, as it indicates that disk is very poor in handling the read requests. |
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Physical layer write throughput |
Indicates the rate at which the data was written on the Physical layer of this disk. |
MB/sec |
A high value is desired for this measure. A very low value is a cause for concern, as it indicates that disk is very poor in handling the write requests. |
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Physical layer read latency |
Indicates the time taken for performing read operations on the Physical layer of this disk. |
Seconds |
Ideally, this value should be low. If not, it implies that the disk is slow in processing the read requests at the Physical layer. |
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Physical layer write latency |
Indicates the time taken for performing write operations on the Physical layer of this disk. |
Seconds |
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Guest IO latency |
Indicates the time taken for performing IO operations on the guests that share this disk. |
Seconds |
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Device IO latency |
Indicates the time taken for performing IO operations on the devices that share this disk. |
Seconds |
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vSAN layer read IOPS |
Indicates the number of read IO operations performed on the vSAN layer of this disk. |
IOPS |
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vSAN layer write IOPS |
Indicates the number of write IO operations performed on the vSAN layer of this disk. |
IOPS |
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vSAN layer read latency |
Indicates the time taken for performing read operations on the vSAN layer of this disk. |
Seconds |
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vSAN layer write latency |
Indicates the time taken for performing write operations on the vSAN layer of this disk. |
Seconds |
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