[Beowulf] best linux distribution

[Mark Hahn]

> "advantages".  There is a narrow line between stability and stagnation,
> and you have to figure out which side of that line your cluster will
> fall on.  Specifically, the fact that Centos/RHEL is frozen for two year
> intervals has two disadvantages for some people:

I think it's wise to always assume that you will be adding
updated packages to your cluster, regardless of which distro
you select.  perhaps there are close-to-turn-key systems where
this is not the case, but anything past a personal cluster
is bound to require some fiddling.

>  a) The hardware it supports is left behind by the real leading edge of
> hardware design.

a valid point, though for the most part, it's really only the 
kernel that has to deal with edgy hardware issues.  your version of 
glibc probably doesn't care for instance.  often, when people report HW
issues with a distro, all they're really talking about is trouble booting 
the install kernel.  of course, there's no need for cluster nodes to be 
using a distros kernel at all, let alone the install-disk's one.

>  b) The libraries it provides are left behind by the real leading edge
> of library development.  Again, this can range in impact from "no big
> deal" to "showstopper", depending on just what libraries your code uses.

and whether you really care about what the distro does.  IMO, any significant
cluster should probably have its own versions of performance- and
security-relevant libraries anyway.  the hardest part of having local
versions is in deciding on a policy on when to update the versions and how to
test.  the actual download/patch/compile/install is a matter of a few
minutes.

> This isn't THAT big a deal, but it is very definitely an added "cost"
> and needs to be considered when making the decision.

right.  IMO, if you're really trying to eliminate costs, just fix
on some distro and freeze the config entirely.  that means not updating
hardware, but you're pinching pennies, right?  it also means minimizing
your exposure to security issues, which should mean agressive firewalling,
limitation of user access, and minimization of the number of installed 
packages.  for instance, why let users login directly?  sure, if there's 
a privilege-elevation exploit, it's probably doable from a batch job,
but it still helps.  I always like to see not-cluster-relevant packages 
removed, as well - probably no need for a printing subsystem, for instance,
or any desktop packages like evolution.

regards, mark hahn.