What's the UID for descartes?  If the user isn't being mastered by a package (like an RPM), it needs to be registered in the allocation reference doc:

https://docs.google.com/a/altiscale.com/spreadsheet/ccc?key=0AgIyMZuBuI9ndDlfNjFRLVA3cWdoTWtyQ0pJal9kVUE&usp=drive_web

Same with the group (second tab in that spreadsheet).

The EPN for this can be read here:
https://docs.google.com/a/altiscale.com/document/d/1Lmpo2HDJFZ7_MXoaf4JcdAUaYg_11eZrlGCLap5PAzM/edit

You'll want to allocate the UID and GID in the system grouping.