Lustre 1.6 Operations Manual

16.3 Isolating and Debugging Failures
In the case of Lustre failures, you need to capture information about what is
happening at runtime. For example some tests may cause kernel panics, depending
on your Lustre configuration. By default, debugging is not enabled in the POSIX test
suite. You need to turn on the VSX debugging options. There are two debug options
of note in the config file tetexec.cfg, under the TESTROOT directory:
VSX_DBUG_FILE=output_file
If you are running the test under UML with hostfs support, use a file on the hostfs as
the debug output file. In the case of a crash, the debug output can be safely written
to the debug file.
Note – The default value for this option puts the debug log under your test
directory in /mnt/lustre/TESTROOT, which is not useful in case of kernel panic
and Lustre (or your machine) crashes.
VSX_DBUG_FLAGS=xxxxx
The following example makes VSX output all debug messages:
VSX_DBUG_FLAGS=t:d:n:f:F:L:l,2:p:P
VSX is based on the TET framework which provides common libraries for VSX. You
can also have TET print out verbose debug messages by inserting the -T option
when running the tests. For example:
$ tcc -Tall5 -e -s scen.exec -a /mnt/lustre/TESTROOT -p 2>&1 | tee
/tmp/POSIX-command-line-output.log
VSX prints out detailed messages in the report for failed tests. This includes the test
strategy, operations done by the test suite, and the failures. Each subtest (for
instance, 'access', 'create') usually contains many single tests. The report shows
exactly which single testing fails. In this case, you can find more information directly
from the VSX source code.
Chapter 16 POSIX 16-5