eG Monitoring
 

Measures reported by EsxDiskUsageTest

This test monitors the space usage of VMFS partitions on an ESX server host.

Measurement Description Measurement Unit Interpretation
Total_capacity Indicates the total capacity of a datastore. For the Total descriptor, this is the total capacity across all datastores used by the target host. MB  
Used_space Indicates the amount of space used in a datastore. For the Total descriptor, this is the total space used across all datastores. MB  
Free_space Indicates the current free space available on every datastore of a host. For the Total descriptor, this is the sum of unused space in all datastores. MB Ideally, the value of this measure should be high.
Percent_usage Indicates the percentage of disk space utilized on every datastore. To know the percentage of total space utilized across all datastores, click on the Total descriptor. Percent A value close to 100% can indicate a potential problem situation where applications executing on the host may not be able to write data to the disk partition(s) with very high usage.

The detailed diagnosis of this measure reveals the top-10 files consuming maximum space in the datastore. The detailed diagnosis capability will not be available for the ‘Total’ descriptor.
Availability Indicates whether/not this VMFS disk partition/datastore is available. Percent While the value 0 indicates that the datastore is not available, the value 100 indicates that the datastore is currently available. The detailed diagnosis of this measure if enabled, will provide you the type of the datastore. This measure is not available for the ‘Total’ descriptor.
Disk_files Indicates the total size of the virtual disk files in this datastore. For the Total descriptor, this is the total size of all virtual disk files in all datastores. MB The detailed diagnosis of this measure, if enabled, lists the disk files on this datastore and the size of each disk file. The detailed diagnosis capability will not be available for the ‘Total’ descriptor.
Snapshot_files Indicates the total size of the snapshot files in this datastore. For the Total descriptor, this is the total size of all snapshot files in all datastores. MB The detailed diagnosis of this measure, if enabled, lists the snapshot files on this datastore and the size of each snapshot file. The detailed diagnosis capability will not be available for the ‘Total’ descriptor.
Swap_files Indicates the total size of the swap files in this datastore. For the Total descriptor, this is the total size of all swap files in all datastores. MB The detailed diagnosis of this measure, if enabled, lists the swap files on this datastore and the size of each swap file. The detailed diagnosis capability will not be available for the ‘Total’ descriptor.
Other_files Indicates the total size of the other VM files in this datastore. For the Total descriptor, this is the total size of all other VM files in all datastores. MB The value of this measure reports the space that is being used by files such as configuration, suspend data, NVRAM, screenshots and others. The detailed diagnosis of this measure, if enabled, lists these files and the size of each such file on this datastore. The detailed diagnosis capability will not be available for the ‘Total’ descriptor.

By comparing the values reported by the Disk files, Snapshot files, Swap files, and Other VM files measures, you can accurately identify the type of files that are occupying too much space on a datastore.
Allocated_Space Indicates the amount of physical space provisioned by an administrator for this datastore. For the Total descriptor, this is the total physical space provisioned for all datastores used by this host. MB This measure reports the storage size up to which files on this datastore (or all datastores) can be stacked.
Total_luns Indicates the number of LUNs through which the host communicates with this datastore. Number This measure is not available for the ‘Total’ descriptor.
Write_Request Indicates the average number of write commands issued per second to this datastore. Commands/Sec These measures are good indicators of the load on a datastore. Compare the values of these measures across datastores to accurately identify the overloaded datastores. Both these measures are not available for the ‘Total’ descriptor.
Read_Request Indicates the average number of read commands issued per second to this datastore. Commands/Sec
Write_Latency Indicates the average amount of time taken to write to this datastore. Secs Very high values for these measures are indicative of processing bottlenecks in a datastore. To know which datastore is experiencing the maximum latency, compare the values of these measures across datastores. Both these measures are not available for the ‘Total’ descriptor.
Read_Latency Indicates the average amount of time taken for a read from the perspective of this datastore. Secs
Storage_Ctrl_Normal Indicates the device latency that the host observes while communicating with this datastore; this latency is a normalized average across virtual machines. Secs Storage I/O Control allows cluster-wide storage I/O prioritization, which allows better workload consolidation and helps reduce extra costs associated with over provisioning.

When you enable Storage I/O Control on a datastore, ESX/ESXi begins to monitor the device latency that hosts observe when communicating with that datastore. When device latency exceeds a threshold, the datastore is considered to be congested and each virtual machine that accesses that datastore is allocated I/O resources in proportion to their shares. You set shares per virtual machine. You can adjust the number for each based on need. This measure is not available for the ‘Total’ descriptor.
Storage_Ctrl_IOPS Indicates the aggregate number of I/O operations that are occuring on this datastore. Number This measure is not available for the ‘Total’ descriptor.
Read_Rate Indicates the rate at which data is read from this datastore. MB/Sec This measure is not available for the ‘Total’ descriptor.
Write_Rate Indicates the rate at which data is written to this datastore. MB/Sec This measure is not available for the ‘Total’ descriptor.
StrCtrl_active_time Indicates whether storage I/O control (SIOC) is active on this datastore or not. Percent Storage I/O Control (SIOC) is used to provide I/O prioritization of virtual machines running on a group of VMware vSphere hosts that have access to a shared storage pool. It extends the familiar constructs of shares and limits, which exist for CPU and memory, to address storage utilization through a dynamic allocation of I/O capacity across a cluster of vSphere hosts.

If SIOC is active, the value of this measure will be 100%. If it is not active, the value of this measure will be 0.
Total_iops Indicates the total number of read and write commands issued per second to this datastore. Commands/Sec Compare the value of this measure across datastores to identify the busiest datastore in terms of the rate at which read/write commands are issued on it. A consistent increase in the value of this measure for a particular datastore could indicate a potential I/O overload.
Total_latency Indicates the total amount of time taken to read and write to this datastore. Secs Ideally, the value of this measure should be low. A high value could indicate an I/O processing bottleneck. By comparing the value of this measure across datastore, you can quickly identify which datastore is the most latent. Such datastores are ideal candidates for enabling SIOC. Enabling IOC on a datastore triggers the the monitoring of device latency that hosts observe when communicating with that datastore. When latency exceeds a set threshold the feature engages automatically as the datastore is experiencing congestion. Each virtual machine that accesses that datastore is then allocated I/O resources in proportion to their shares.
Throughput Indicates the rate at which the data is read and written to this datastore. MB/Sec Ideally, the value of this measure should be high. A steady decrease in the value of this measure could indicate that the datastore is experiencing a congestion. You may want to enable SIOC on such datastores, so that when latency exceeds a set threshold the SIOC feature engages automatically and then allocates I/O resources to each VM that acceses that datastore in proportion to their shares.