Constant Workloads

Access Pattern

The access pattern has one configurable parameter: the read/write ratio. The CDB Length is not yet configurable, but it provides a read-only display to confirm the CDB Length that is used for the workload.

To change the read/write ratio, drag the slider to the right to increase the read percentage or to the left to increase write percentage.

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Writes and Reads

Using the writes and reads section, you can configure the block sizes, percentage of random versus sequential behaviors, and several other parameters.

There is a separate section in the UI for writes and reads, the configuration options are similar. See Creating a New Workload Test. FC-NVMe workloads provide some different parameters and terminologies.

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You can specify the I/O region of the Namespace using absolute values or a percentage of the Namespace for the overall size and offset. To change the method, select the drop-down menu next Configure I/O Region as.

If you specify an absolute value in bytes, kilobytes (KB), megabytes (MB) or gigabytes (GB), only that sized region starting at specified offset is used. To change the absolute values, edit the offset and region sizes or percentages in the text boxes.

If you specify a percentage, the starting offset and the overall region are calculated by the workload.

If you want to use the same parameters for reads and writes, check the Use the same parameters as in Writes checkbox in the Reads section.

Data Parameters

FC-NVMe constant workloads support the following data parameters options:

  • Constant: all zeroes

  • Sequential: incrementing counter of a 32-bit number

  • Random: randomly generated numbers that are not reproducible

  • Seeded Random: randomly generated numbers that are reproducible with the same seed value

  • Data Reduction

    • Dedup Ratio: the desired resulting ratio of transmitted data versus stored data after duplicated data is removed.

    • Duplicate uniqueness percent: the desired percentage of duplicate uniqueness, from 0% to 100%.

When writing dedup patterns, duplicates are written in order to meet the desired dedup ratio. These duplicates can be mostly identical (minimal duplicate uniqueness) or can mostly be unique (maximal duplicate uniqueness). A small DupUniq value leads to a small amount of device space being required to store duplicates. A large DupUniq value leads to a large amount of device space being required to store duplicates.

  • Compression Ratio: the desired resulting ratio of transmitted data versus stored data after compressible data is compressed.

NVMe Settings

Specify the total number of concurrent NVMe Queues and the total depth of each NVMe Queue.

  • Queue Count: default is 32. Max is 32.

  • Queue Depth: default is 1,024. Max is 1,024.

Preconditioning

A dedicated Preconditioning workload is not yet available for FC-NVMe. To precondition a device, simply run an FC-NVMe workload test with 100% write and the desired data content, and set the I/O Region to 100% of the Namespace.

MPIO

MPIO is only available when enabled on the test bed on which the workload is running. There are two MPIO algorithms currently supported:

  • Fail over only. Ensures the I/O is redirected to an operational port.

  • Round robin. Distributes the load across all ports participating in MPIO.