NetApp E-Series Storage Volume Workload Test

This test monitors the storage volumes in the target NetApp E-Series Storage system and reports the I/O processing ability of each storage volume in terms of reads/writes, cache/flash cache hits, etc. In addition, this test helps the administrators to identify the storage volume that is taking too long to respond to read/write requests.

Target of the test : NetApp E-Series Storage

Agent deploying the test : A remote agent

Outputs of the test : One set of results for each storage volume in the NetApp E-Series Storage that is currently launched.

Configurable parameters for the test
Parameters	Description
Test Period	How often should the test be executed.
Host	The nick name of the NetApp E-Series Storage component for which this test is to be configured.
Port	Refers to the port at which the specified host listens to. By default, this is Null.
Rest API Port	This is the port at which REST API connectivity is provided. By default, port 4443 is used.
Username and Password	To collect performance metrics from the target storage device, the eG agent should be configured with the credentials of a user who is vested with "read-only" privileges to access REST API of the target storage device. Specify the credentials of such a user in the Username and Password text boxes.
Confirm Password	Confirm the password by retyping it here.
SSL	Set the SSL flag to Yes, if SSL (Secured Socket Layer) is to be used to connect to the target Storage System, and No if it is not.
Timeout Seconds	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
Read IOPS	Indicates the rate at which read I/O operations were performed on this storage volume.	Reads/sec	Compare the values of these measures across the storage volumes to know what is contributing to the abnormal I/O activity levels - read operations? or write operations?
Write IOPS	Indicates the rate at which write I/O operations were performed on this storage volume.	Writes/sec
Other IOPS	Indicates the rate at which other I/O operations were performed on this storage volume.	Operations/sec
Read throughput	Indicates the rate at which data was read by this storage volume.	MB/sec
Write throughput	Indicates the rate at which data was written by this storage volume.	MB/sec
Read response time	Indicates the time taken for this storage volume to respond to a read request.	Milliseconds
Write response time	Indicates the time taken for this storage volume to respond to a write request.	Milliseconds
Average read operation size	Indicates the total size of data read from this storage volume.	MB
Average write operation size	Indicates the total size of data written on this storage volume.	MB
Read hits	Indicates the number of hits received by this storage volume to perform read operations.	Hits	A consistent drop in the value of this measure is indicative of ineffective read/write cache usage, which can lead to a slowness in read/write request servicing.
Write hits	Indicates the number of hits received by this storage volume to perform write operations.	Hits
Read hit data	Indicates the amount of data read by this storage volume.	MB
Write hit data	Indicates the amount of data written on this storage volume.	MB
Read cache utilization	Indicates the percentage of cache utilized to perform read operations in this storage volume.	Percent
Write cache utilization	Indicates the percentage of cache utilized to perform write operations in this storage volume.	Percent
Flash cache read hits	Indicates the number of times data was read from the flash cache in this storage volume.	Hits	Flash cache uses solid-state drives (SSDs) to temporarily store frequently accessed data. The goal of flash cache is to improve system performance by reducing the need for disk I/O operations, which are slower compared to accessing data from flash memory. When data is read from disk storage, the flash cache checks if that data is already in the cache. If it's not, it will read the data from disk and store it in the cache for future requests. If the data is requested again, the system can serve it from the much faster flash cache, resulting in lower latency and improved performance. Ideally, the value of these measures should be high. A consistent drop in this value is a cause for concern, as it could indicate that data is not read from the flash cache frequently. This in turn implies low flash cache usage and high disk usage.
Flash cache read hit data	Indicates the amount of data that was read from the flash cache in this storage volume.	MB
Random I/O percentage	Indicates the percentage of random IO operations performed by this storage volume.	Percent	A high Random I/O percentage indicates workloads that are more likely to stress the system, particularly in terms of IOPS . This is because random access patterns are harder for the storage system to handle compared to sequential ones.
Random data percentage	Indicates the percentage of data accessed by this storage volume randomly.	Percent
Cache write wait operations percentage	Indicates the percentage of time the write requests in this storage volume spend waiting for the cache to be ready to process them.	Percent
Cache write wait data percentage	Indicates the percentage of data that is waiting to be written in the cache before it can be written to this storage volume.	Percent
Prefetch hit percentage	Indicates the percentage of pre-fetch operations that were successful in this storage volume.	Percent	Prefetching is a technique used to improve read performance by anticipating which data will be needed next and loading it into cache before the request is made. A low hit percentage suggests that prefetching is not effectively predicting data access patterns, resulting in more cache misses and higher latency as data must be fetched from slower storage. This could lead to performance degradation, especially for workloads that rely on fast, sequential data access.
Read hit response time	Indicates the time taken for this storage volume to respond to a read request.	Milliseconds
Write hit response time	Indicates the time taken for this storage volume to respond to a write request.	Milliseconds