TotalView Users Guide - CI Wiki

Debugging Cray XT Applications
For information on setting server launch strings, see “Setting Up and Starting
the TotalView Server” on page 81.
While debugging, you must also have the FlexLM license server running. TotalView uses
this server to verify that you are using licensed software. However, this server is not
related to the servers that TotalView launches when you are debugging your program.
Configuring TotalView
When configuring your Cray XT system for use with the TotalView, you must:
� Mount user home directories on all service nodes that you will use while
debugging.
� (Optional) Enable passwordless ssh on all service nodes that you will use
while debugging. In most cases, your system administrator will have enabled
your system so that it uses ssh instead or rsh. If passwordless ssh
is not enabled, you will be asked to enter a password each time a process
is launched on a node.
� (Optional) Automatically set RS_DBG_CLIENTS_PER_SERVER and
–nodes_allowed.
On Cray XT systems setting a –nodes_allowed command-line option to 64
will not work. Instead, you should configure TotalView to use
RS_DBG_CLIENTS_PER_SERVER and –nodes_allowed to make best use of the
cluster and TotalView licenses.
TotalView administrators can set installation preferences by editing (or creating)
the $TVROOT/linux-x86-64/lib/.tvdrc file. Here are two simple scenarios
� If you only have one TotalView license and that license is for less than 64
processors then a server launch string like this would be best:
dset -set_as_default TV::server_launch_string \
{%C %R -n "%B/tvdsvr%K -working_directory %D \
-callback %L \
-nodes_allowed maximum_processor_license \
-set_pw %P -verbosity %V %F"}
where maximum_processor_license is the processor count for your TotalView
license.
� If you will be running TotalView on a cluster where the ratio of service
nodes to compute nodes is less than 1:64, you should use a server
launch string. For example:
dset -set_as_default TV::server_launch_string \
{%C %R -n "%B/tvdsvr%K -working_directory %D \
-callback %L \
-nodes_allowed ${RS_DBG_CLIENTS_PER_SERVER-64} \
-set_pw %P -verbosity %V %F"}
You will need to set the RS_DBG_CLIENTS_PER_SERVER environment variable
before submitting all jobs where a service node-to-compute node
ration of 1:64 is not possible. You should also set
RS_DBG_CLIENTS_PER_SERVER to the number of compute nodes served
by each service node. For example, if you have a service-to-node ratio of
1:128, set this variable to 128.
TotalView Reference Guide: version 8.7 145