[CentOS] Cemtos 7 : Systemd alternatives ?

Tue Jul 8 17:27:03 UTC 2014
Les Mikesell <lesmikesell at gmail.com>

On Tue, Jul 8, 2014 at 11:25 AM, Lamar Owen <lowen at pari.edu> wrote:
> Memory tests are redundant with ECC. (I
> know; I have an older SuperMicro server here that passes memory testing
> in POST but throws nearly continuous ECC errors in operation; it does
> operate, though).  If it fails during spinup, flag the failure while
> spinning up another server.

I don't think that is generally true.  I've seen several IBM systems
disable memory during POST and come up running will a smaller amount.

> Virtual servers have no need of POST (they also don't save as much
> power; although dynamic load balancing can do some predictive heuristics
> and spin up host hypervisors as needed and do live migration of server
> processes dynamically).

Our services that need scaling need all of the hardware capability and
aren't virtualized.   That might change someday...

> To detect failures early, spin up every server in a rotating sequence
> with a testing instance, and skip POST entirely.
>
> If you have to, spin up the server in a stateless mode and put it to
> sleep.  Then wake it up with dynamic state.

Our servers tend to just run till they die.  If we didn't need them we
wouldn't have bought them in the first place.  I suppose there are
businesses with different processes that come and go, but I'm not sure
that is desirable.

> Long POSTs need to go away, with better fault tolerance after spinup
> being far more desirable, much like the promise of the old as dirt
> Tandem NonStop system. (I say the 'promise' rather than the
> 'implementation' for a reason.....).

If you need load balancing anyway you just run enough spares to cover
the failures.

-- 
   Les Mikesell
      lesmikesell at gmail.com