Chris Green wrote: > Matus UHLAR - fantomas wrote: > > > chris@isbdGandi$ more /etc/hosts > > > 127.0.0.1 isbdGandi.isbd.uk isbdGandi isbd localhost > > > > no no no. > > 127.0.0.1 is always supposed to resolve to "localhost". > > If those hosts don't have their assigned IP, Debian uses "127.0.1.1" for > > their hostnames.
+1. Strong agreement. > Given that some of my systems have their IP address allocated > dynamically there's not really much alternative except to put the > system's name against 127.0.0.1. Lots of things *do* rely on the name > being there. (or for 127.0.1.1). If you are already going to edit /etc/hosts then you have already committed to having a unique file on each system. But instead of abusing the 127.0.0.1 entry use a different loopback address such as the typical 127.0.1.1 address which provides an always available address and avoids the problems created by diverting localhost. I have managed large compute pools before. Large being single digit thousands. (Okay, my peak was 3,856 systems.) If one tries to rely upon network interaction such as a DNS lookup in order to set critical information such as the hostname then at a low rate there will be failures when the network lookup fails. And then nodes get set with an unusable or invalid hostname. If something has a low failure rate but is done often enough then it will be seen in practice at some annoying rate. I choose to avoid failures like this. It's simple enough avoid the problem in this case. Bob
