client/tests/ffsb/README

INTRODUCTION:
=============
This patch integrates the Flexible Filesystem Benchmark (FFSB) with
the autotest. This integration enables the high-performace I/O load testing in the
KVM Virtual machine environment.

FFSB is a filesystem performance measurement tool.  It is a multi-threaded
application (using pthreads), written entirely in C with cross-platform
portability in mind.  It differs from other filesystem benchmarks in that
the user may supply a profile to create custom workloads, while most other
filesystem benchmarks use a fixed set of randomly generated workloads.

More information about the FFSB can be got from reading the README in the
FFSB source directory which can be accessed from this link:
[http://sourceforge.net/projects/ffsb/]

With this integration, it is now possible to test a variety of filesystems on
the KVM guest for :

(1) directed I/O with sequential/random read/write.
(2) buffered I/O with sequential/random read/write.
(3) use varying block alignment boundaries to measure filesystem behaviour.
(4) use multithreaded workloads to stress the filesystem.
(5) Exert weighted combination of I/O workloads to analyze the I/O performace
    for a specific scenario.
(6) Age filesystem according to a specified workload upto a specified limit.

    Since the only interface used for the integration is a FFSB configuration file;
Autotest will be able to run variety of I/O tests on guest as FFSB improves,
with no or minimal code change in Autotest itself.

USE:
====
To use the FFSB for Filesystem testing, two configuration files
need to be modified -
(1) Usual - tests.cfg file to activate the ffsb tests through KVM.
(2) profile.cfg - where the workloads are specified.

TODO:
====
* Add validations for max. number of threads according to number of
  vcpus exported by QEMU-KVM
* Test Autotest/ffsb
* Test FFSB itself.