And for continuity, I'll point out that there was a similar, lengthy
discussion on this topic in September 2011.

Here is the thread started by Tanmoy Chatterjee:

http://listserv.fnal.gov/scripts/wa.exe?A2=ind1109&L=SCIENTIFIC-LINUX-USERS&T=0&I=-3&X=5E3D186375663BCF45&Y=slasiewski%40lbl.gov&P=26572