Disk Activity - OS Test
This test reports statistics pertaining to the input/output utilization of each physical disk on a guest.
Target of the test: Oracle VM Server
Agent deploying the test: A remote agent
Outputs of the test: One set of results for each disk partition on each powered-on VM of the Oracle VM Server being monitored.
Parameters | Description |
---|---|
Test Period |
How often should the test be executed. |
Host |
The host for which the test is to be configured. |
Port |
The port at which the specified Host listens. By default, this is NULL. |
Oracle VM Manager, Oracle VM Manager User, Oracle VM Manager Password, and Confirm Password |
This test remotely connects to the Oracle VM Manager that manages the monitored Oracle VM Server and uses the web services API of the Oracle VM Manager to pull out metrics of interest. To enable this test to communicate with the web services API, you first need to configure the test with the IP address or host name of the Oracle VM Manager. This can be done using the Oracle VM Manager text box. Then, you need to configure the test with the credentials of a user with Admin rights to the Oracle VM Manager. Use the Oracle VM Manager User and Oracle VM Manager Password parameters to configure these credentials. Finally, confirm the password by retyping it in the Confirm Password text box. |
SSL |
By default, the Oracle VM Manager is SSL-enabled. Accordingly, the SSL flag is set to Yes by default. This indicates that the eG agent will communicate with the Oracle VM Manager via HTTPS by default. |
WebPort |
By default,, the Oracle VM Manager listens on 7002. This implies that while monitoring an Oracle VM server via an SSL-enabled Oracle VM Manager, the eG agent, by default, connects to port 7002 of the Oracle VM Manager to pull out metrics. In some environments however, this default port may not apply. In such a case, against the WebPort parameter, you can specify the exact port at which the Oracle VM Manager in your environment listens so that the eG agent communicates with that port. |
Exclude VMs |
Administrators of some virtualized environments may not want to monitor some of their less-critical VMs - for instance, VM templates - both from 'outside' and from 'inside'. The eG agent in this case can be configured to completely exclude such VMs from its monitoring purview. To achieve this, provide a comma-separated list of VMs to be excluded from monitoring in the Exclude VMs text box. Instead of VMs, VM name patterns can also be provided here in a comma-separated list. For example, your exclude vms specification can be: *xp,*lin*,win*,vista. Here, the * (asterisk) is used to denote leading and trailing spaces (as the case may be). By default, this parameter is set to none indicating that the eG agent obtains the inside and outside views of all VMs on a virtual host by default. By providing a comma-separated list of VMs/VM name patterns in the Exclude VMs text box, you can make sure the eG agent stops collecting 'inside' and 'outside' view metrics for a configured set of VMs. |
Ignore VMs Inside View |
Administrators of some high security Oracle environments might not have permissions to internally monitor one/more VMs. The eG agent can be configured to not obtain the 'inside view' of such ‘inaccessible’ VMs using the Ignore VMs Inside View parameter. Against this parameter, you can provide a comma-separated list of VM names, or VM name patterns, for which the inside view need not be obtained. For instance, your ignore vms inside view specification can be: *xp,*lin*,win*,vista. Here, the * (asterisk) is used to denote leading and trailing spaces (as the case may be). By default, this parameter is set to none indicating that the eG agent obtains the inside view of all VMs on an Oracle VM server by default. Note: While performing VM discovery, the eG agent will not discover the operating system of the VMs configured in the ignore vms inside view text box. |
Inside View Using |
By default, this test communicates with every VM remotely and extracts “inside view” metrics. Therefore, by default, the inside view using flag is set to Remote connection to VM (Windows). Typically, to establish this remote connection with Windows VMs in particular, eG Enterprise requires that the eG agent be configured with domain administrator privileges. In high-security environments, where the IT staff might have reservations about exposing the credentials of their domain administrators, this approach to extracting “inside view” metrics might not be preferred. In such environments therefore, eG Enterprise provides administrators the option to deploy a piece of software called the eG VM Agent (Windows) on every Windows VM; this VM agent allows the eG agent to collect “inside view” metrics from the Windows VMs without domain administrator rights. To ensure that the “inside view” of Windows VMs is obtained using the eG VM Agent, set the inside view using flag to eG VM Agent (Windows). Once this is done, you can set the Domain, Admin User, and Admin Password parameters to none. |
Ignore WINNT |
By default, the eG agent does not support the inside view for VMs executing on Windows NT operating systems. Accordingly, the Ignore WINNT flag is set to Yes by default. |
Domain, Admin User, Admin Password, and Confirm Password |
By default, this test connects to each virtual guest remotely and attempts to collect “inside view” metrics. In order to obtain a remote connection, the test must be configured with user privileges that allow remote communication with the virtual guests. The first step towards this is to specify the Domain within which the virtual guests reside. The admin user and admin password will change according to the domain specification. Discussed below are the different values that the domain parameter can take, and how they impact the admin user and admin password specifications:
|
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:
|
Measurement | Description | Measurement Unit | Interpretation |
---|---|---|---|
Percent virtual disk busy |
Indicates the percentage of elapsed time during which the disk is busy processing requests (i.e., reads or writes). |
Percent |
Comparing the percentage of time that the different disks are busy, an administrator can determine whether load is properly balanced across the different disks. |
Percent reads from virtual disk |
Indicates the percentage of elapsed time that the selected disk drive is busy servicing read requests. |
Percent |
|
Percent writes to virtual disk |
Indicates the percentage of elapsed time that the selected disk drive is busy servicing write requests. |
Percent |
|
Virtual disk read time |
Indicates the average time in seconds of a read of data from the disk. |
Secs |
|
Virtual disk write time |
Indicates the average time in seconds of a write of data from the disk. |
Secs |
|
Avg. queue for virtual disk |
Indicates the average number of both read and write requests that were queued for the selected disk during the sample interval. |
Number |
|
Current queue for virtual disk |
The number of requests outstanding on the disk at the time the performance data is collected. |
Number |
This measure includes requests in service at the time of the snapshot. This is an instantaneous length, not an average over the time interval. Multi-spindle disk devices can have multiple requests active at one time, but other concurrent requests are awaiting service. This counter might reflect a transitory high or low queue length, but if there is a sustained load on the disk drive, it is likely that this will be consistently high. Requests experience delays proportional to the length of this queue minus the number of spindles on the disks. This difference should average less than two for good performance. |
Reads from virtual disk |
Indicates the number of reads happening on a logical disk per second. |
Reads/Sec |
A dramatic increase in this value may be indicative of an I/O bottleneck on the guest. |
Data reads from virtual disk |
Indicates the rate at which bytes are transferred from the disk during read operations. |
KB/Sec |
A very high value indicates an I/O bottleneck on the guest. |
Writes to virtual disk |
Indicates the number of writes happening on a local disk per second. |
Writes/Sec |
A dramatic increase in this value may be indicative of an I/O bottleneck on the guest. |
Data writes to virtual disk |
Indicates the rate at which bytes are transferred from the disk during write operations. |
KB/Sec |
A very high value indicates an I/O bottleneck on the guest. |
Disk service time |
Indicates the average time that this disk took to service each transfer request ( i.e., the average I/O operation time) |
Secs |
A sudden rise in the value of this measure can be attributed to a large amount of information being input or output. A consistent increase however, could indicate an I/O processing bottleneck. |
Disk queue time |
Indicates the average time that transfer requests waited idly on queue for this disk. |
Secs |
Ideally, the value of this measure should be low. |
Disk I/O time |
Indicates the average time taken for read and write operations of this disk. |
Secs |
The value of this measure is the sum of the values of the Disk service time and Disk queue time measures. A consistent increase in the value of this measure could indicate a latency in I/O processing. |
Avg IO read size |
Indicates the average number of bytes transferred from disk during read operations. |
KB |
Larger I/Os tend to have higher latency (for example, BACKUP/RESTORE operations issue 1 MB transfers by default). These measures are reported for Windows VMs only. |
Avg IO write size |
Indicates the average number of bytes transferred into disk during write operations. |
KB |
|
Split IO |
Reports the rate at which the operating system divides I/O requests to the disk into multiple requests. |
Splits/Sec |
A split I/O request might occur if the program requests data in a size that is too large to fit into a single request or if the disk is fragmented. Factors that influence the size of an I/O request can include application design, the file system, or drivers. A high rate of split I/O might not, in itself, represent a problem. However, on single-disk systems, a high rate for this counter tends to indicate disk fragmentation. This measure is reported for Windows VMs only. |