Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I am trying to configure two pc for working with openMPI, i installed openmpi and openssh on the PCs but when i execute: mpirun -np 4 -host slave ./a.out

i get:

[slave-901:07002] Error: unknown option "--tree-spawn"
[Master:04772] [[61643,0],0] ORTE_ERROR_LOG: Data for specified key not found in file          base/grpcomm_base_xcast.c at line 166
share|improve this question

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.