MEXTEX Help

1. Overview

In the manual mode, MEXTEX starts up a number of independent threads, for each device currently open, each capable of issuing one outstanding I/O at a time. The user specifies the inter I/O time and a script defining the sequence of LBAs associated with each I/O the thread generates.

In the advanced mode, MEXTEX starts up a number of independent scheduler threads, for each device currently open, each of which can generate a number of outstanding I/Os. The maximum number of outstanding I/Os depends on the maximum number of processes which can be started on the target machine. The user has access to advanced controls for controlling the distribution of I/O parameters.

Operating parameters can be saved/restored to/from files either by direct manipulation of the GUI menu, or through a remote control facility.

Performance statistics are collected for each device being exercised, displayed on a seperate statistics window and updated periodically, the period being adjustable. These statistics can be dumped to a file either by direct manipulation of the GUI menu, or through a remote control facility.

MEXTEX has the capability of generating an event trace of I/Os issued. Event tracing needs to be enabled before a trace file can be generated. This trace file can then be viewed graphically with a program called graphtrace.

MEXTEX has the capability of triggering on abnormal events, where abnormal events are defined as I/Os which required a exceptional time to complete. Event triggering needs to be enabled before it is functional. When an abnormal event trigger occurs, a record of the the event will be made in the event trace (if event tracing is enabled), and/or all I/O threads can be optionally stopped, and/or a user defined SCSI command will be issue to a user defined physical I/O device.

MEXTEX has the capability of generating data patterns, during write I/Os, and verifying those patterns, during read I/Os.