eG Monitoring
 

Measures reported by VsanPhysicalDTest

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.

Outputs of the test : One set of results for VMware vCenter server that is being monitored.

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Drive_type Indicates the drive type of this physical disk.   The values that this measure can report and their corresponding numeric values have been listed in the table below:

Numeric Value Measure Value
0 FLASH
1 HDD

Note:

By default, this measure reports 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.
Drive_type Indicates the drive type of this physical disk.   The values that this measure can report and their corresponding numeric values have been listed in the table below:

Numeric Value Measure Value
0 FLASH
1 HDD

Note:

By default, this measure reports 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.
Health Indicates the current health of this physical disk.   The values that this measure can report and their corresponding numeric values have been listed in the table below:

Numeric Value Measure Value
0 Healthy
1 Disk health is unknown
2 Permanent disk failure
3 Permanent disk loss
4 Disk dicommissioned
5 Disk performance degraded, and components are evacuating
6 Disk performance degraded, and component evacuation failed
7 Disk performance degraded, and component evacuation get stuck
8 Disk performance degraded, and dying disk is ok to unmount

Note:

By default, this measure reports 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.
Capacity Indicates the total capacity of this disk. GB  
Used_capacity Indicates the amount of space utilized on this disk. GB  
Used_Utilization Indicates the percentage of space utilized on this disk. Percentage  
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.
Reserved_Utilization Indicates the percentage of space that is reserved on this disk for Thick Provisioning. Percentage  
Iops_dev_read 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.
Iops_dev_write 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.
Throughput_dev_read 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.
Throughput_dev_write 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.
Latency_dev_read 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.
Latency_dev_write Indicates the rate at which the data was written on the Physical layer of this disk. Seconds  
Latency_devg_avg Indicates the time taken for performing IO operations on the guests that share this disk. Seconds  
Latency_devd_avg Indicates the time taken for performing IO operations on the devices that share this disk. Seconds  
Iops_dev_readv Indicates the number of read IO operations performed on the vSAN layer of this disk. IOPS  
Iops_dev_writev Indicates the number of write IO operations performed on the vSAN layer of this disk. IOPS  
Latency_read Indicates the time taken for performing read operations on the vSAN layer of this disk. Seconds  
Latency_write Indicates the time taken for performing write operations on the vSAN layer of this disk. Seconds