Exadata Grid Disk Status Test

A cell disk created on the target Oracle Exadata Storage Server can be further sub divided into grid disks which can be further exposed to Oracle ASM as disks. Grid disks are the logical storage entities on the storage cell upon which ASM disks can be discovered and ASM disk groups can be built. An Oracle Automatic Storage Management (Oracle ASM) disk group is the primary storage abstraction within Oracle ASM, and is composed of one or more grid disks. Exadata administrators are encouraged to strive for equally sized, well-balanced grid disk configurations. Doing so enables Exadata to maximize disk I/O bandwidth, I/Os per second, and ultimately ensure a well-balanced, high-performing storage platform on Exadata. If a grid disk is inactive or not available, then, users may be deprived access to the data available on that grid disk. This will also lead to an imbalance in the disk I/O bandwidth and eventually affect the performance of the storage server. To avoid such adversities and to ensure that the storage server is always at its peak performance, it is essential to monitor the status of the grid disks periodically. The Exadata Grid Disk Status test helps administrators in this regard!

This test auto-discovers the grid disks created on each ASM disk group and reports the status of each grid disk. Using this test, administrators can identify inactive disks and analyze the reason behind the grid disks being inactive. This test also reports the count of errors encountered by each grid disk. Administrators can figure out the grid disk that is most frequently prone to errors and can initiate remedial measures to avert such errors.

Target of the test : Oracle Exadata Storage Server

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each ASM disk group:grid disk combination of the target Oracle Exadata Storage Server that is being monitored

Configurable parameters for the test

Parameter	Description
Test period	How often should the test be executed
Host	The IP address of the host for which this test is to be configured.
Port	The port number at which the specified host listens. By default, this is NULL.
Username, Password and Confirm Password	By default, this test uses the Cell Control Command-Line Interface (CellCLI) to pull out the required metrics. To use the CLI, the test first needs to connect to the target storage server via SSH, and then run commands using CLI. For running the commands, this test requires the credentials of a cellmonitor user. Specify the login credentials of such a user in the Username and Password text boxes and confirm the Password by retyping it in the Confirm Password text box.
SSH Port	This test uses the Cell CLI to pull metrics from the target Oracle Exadata Storage Server. To run the CLI commands, this test first needs to establish an SSH connection with the target storage server. To enable the test to establish this connection, specify the SSH Port here.
Timeout	Specify the time duration for which this test should wait for a response from the storage system in the Timeout text box. By default, this is 120 seconds.

Measurements made by the test

Measurement	Description	Measurement Unit	Interpretation
Grid disk status	Indicates the current status of this grid disk.		The table below indicates the values that this measure can report and their corresponding numeric equivalents: Measure value Numeric Value Active 100 Import required 90 Inactive 50 Not present 0 Note: By default, this measure reports the above-mentioned Measure Values while indicating the current status of the grid disk. However, in the graph of this measure, the status of the grid disk will be represented using the corresponding numeric equivalents only.
Error count	Indicates the number of errors encountered by this grid disk.	Number	Ideally, the value of this measure should be zero. Compare the value of this measure across grid disks to identify the grid disk that is most frequently prone to errors.