3.4. General Run-Time Support Notes
- The PMIx installation must be in your - PATHon all nodes (and potentially- LD_LIBRARY_PATHor- DYLD_LIBRARY_PATH, if- libpmixis a shared library).
- PMIx’s run-time behavior can be customized via Modular Component Architecture (MCA) parameters (see the MCA section for more information on how to get/set MCA parameter values). 
- If specified, we recommend that the - ptl_tcp_if_includeparameter include the loopback device (- loon many Linux platforms) to ensure that at least one intra-node transport can be found between a local client and its server. For example:- export PMIX_MCA_ptl_tcp_if_include lo,eth1 ...
- Running on nodes with different endian and/or different datatype sizes within a single PMIx-based application is supported in this release, at least from a PMIx perspective (i.e., we will pack/unpack to handle the situation). However, PMIx does not resize data when the same datatype differs in size (for example, sending a 4 byte - doubleand receiving an 8 byte- doublewill fail).