essstress command

Runs a stress test on the file system with different options.

Synopsis


essstress [ -t Threads ] [ -i Iterations ] [ -b BlockSize ] 
          [ -s FileSize ] [ -o OperationList ] [ -p IoPattern ] [ -f FileName ]
		  TargetPath Node1 [Node2...NodeN] [ -h | --help ]

Availability

Available with IBM Storage Scale System.

Description

The essstress command can be invoked from the management server node (EMS) to run stress tests on the file system with different options.

Parameters

-t NumThreads

Specifies the number of simultaneous threads. The default is 16.

-i Iterations

Specifies the number of iterations of read-write operations to be performed on the file system. The default is 20.

-b BlockSize

Specifies the block size to be used for the stress test. The default is 16M.

-s FileSize

Specifies the size of the file to be used for the stress test. The default is 200G.

-o OperationList

Specifies the I/O operation type to be performed while running the stress test. Valid values are: create, read, write, read. The default is create.

-p IoPattern

Specifies the I/O pattern to be used for the stress test. Valid values are: seq (for sequential), rand (for random access). The default is seq.

-f FileName

Specifies the base file name used in the stress test. The default is stressFile. The file names for the tests are generated as: FileName.Iteration.NodeWhereRunning. For example: stressFile.1.gssio1, stressFile.2.gssio1,.... for iterations 1 and 2 on node gssio1.

TargetPath

Specifies the GPFS file system mount point on which the stress test is performed.

Node1 [Node2...NodeN]

Is a space-separated list of nodes where the stress test is run. Do not use commas between the node names. For example:


gssio1 gssio2

The node must have file system mounted on it before performing any stress test.

-h | --help

Displays usage information about this command and exits.

Exit status

0: Successful completion.
nonzero: A failure has occurred.

Security

You must have root authority to run the essstress command.

Example

This example shows how to run the stress test on GPFS file system /gpfs/gpfs0.

# mmmount gpfs0 -a
# essstress /gpfs/gpfs0 gssio1 gssio2

In this example, essstress is invoked on the management server node. It is run on I/O server nodes gssio1 and gssio2 with /gpfs/gpfs0 as the target path. By default, essstress runs for 20 iterations, which can be adjusted using the -i option.

Location

/opt/ibm/ess/tools/bin