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BLAST Workload

BLAST is an IBM internal program that is a disk, tape, and tape library exerciser. It is a multi-threaded program capable of exercising disk, tape, and tape library devices attached locally, or through a network. It uses system calls to test these storage devices in much the same way that a customer would use them. It uses standard system calls similar to what a customer application would use. It checks the return code from every operation, and verifies all data.

A BLAST program based workload has been used to generate disk I/O from a Linux guest virtual machine. This is an example of a command to start a BLAST Write Verify Loop to generate disk I/O:


WRITE_VERIFY_LOOP - This test writes data to files in a directory. When the appropriate number of files have been written, it reads and verifies the file contents. It then, copies the files to additional directories, and compares them with the files in the source directory. This process repeats until the disk is full. All files and directories are removed, and the cycle repeats until stopped.

MNT_PNT= - The name of the file system to be tested.

FILES= - The number of files per directory.

IMMED - Performs immediate compares on files.

GIANT - Creates Giant files. Giant files are files made up of blocks of 1024 sectors. All read and write operations are for 524288 bytes.

MAX_DATA= - Maximum amount of data to write for an iteration, specified in megabytes.

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