Oracle ZFS ARC Size Test

The ARC (Adaptive Replacement Cache) size shows the size of the primary file system cache, the DRAM based ZFS ARC. The ARC should automatically increase in size to fill most of available DRAM, when enough data be accessed by the current workload to be placed in the cache. The breakdown allows the contents of the ARC to be identified by type. This may also be checked when using cache devices (L2ARC) on systems with limited DRAM, as the ARC can become consumed with L2ARC headers.

Using the Oracle ZFS ARC Size test, the administrator can analyze and understand the average ARC data size, header size, and when high utilization had occurred.

Target of the test : Oracle ZFS Storage System

Agent deploying the test : A remote agent

Outputs of the test : One set of results for the Oracle ZFS Storage System being monitored.

Configurable parameters for the test
Parameter	Description
Test period	How often should the test be executed.
Host	The IP address of the target system that is being monitored.
Port	The port number through which Oracle ZFS Storage System communicates. The default port is 215.
User, Password and Confirm Password	By default, this test uses the REST API commands to pull out the required metrics. To execute the REST API commands, the eG agent requires the permission of a local administrator user who has been assigned with Basic role and a custom role with Analytics authorization and read permission. Specify the 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. To create a new user with the required permissions, refer Creating a new user on Oracle ZFS Storage System.
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 60 seconds.
Num DD Messages	By default, the NUM DD MESSAGES parameter is set to 10. This means that, by default, the detailed diagnosis of this test will report the details of the top-10 records of the measures that are obtained upon execution of this test. To view the details of more records as part of detailed metrics, you will have to increase the value of this parameter. Likewise, to view the details of less than 10 records, reduce the value of this parameter.
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: The eG manager license should allow the detailed diagnosis capability Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.

Measurements made by the test
Measurement	Description	Measurement Unit	Interpretation
ARC size	Indicates the current ARC Size.	GB
Average ARC data size	Indicates the average ARC data size during the last measurement period.	GB
Peak ARC data size	Indicates the peak ARC data size during the last measurement period.	GB	Use the detailed diagnosis of this measure to know when cached contents, including file system data and file system metadata had been highly utilized.
Average ARC headers size	Indicates the average ARC headers size during the last measurement period.	GB
Peak ARC headers size	Indicates the peak ARC headers size during the last measurement period.	GB	Use the detailed diagnosis of this measure to know when metadata of the ARC had been highly utilized.
Average ARC others size	Indicates the average ARC other size during the last measurement period.	GB
Peak ARC others size	Indicates the peak ARC other size during the last measurement period.	GB	Use the detailed diagnosis of this measure to know when kernel members other than ARC header and ARC data had been highly utilized.
Average L2ARC headers size	Indicates the average L2ARC headers size during the last measurement period.	GB
Peak L2ARC headers size	Indicates the peak L2ARC headers size during the last measurement period.	GB	Use the detailed diagnosis of this measure to know when L2ARC headers had been highly utilized.