[CentOS] Hot swap CPU

Thu Jun 30 20:16:48 UTC 2005
Bryan J. Smith <b.j.smith@ieee.org> <thebs413 at earthlink.net>

From: Peter Arremann <loony at loonybin.org>
> Actually that was exactly the point. The email I responded to was
> mentioning ancient US-I/II frames as a solution for the hotswap issue. My
> point was that for the same cost I can get a 8way E4500/400/4MB or a nice
> P4 PC... 
> From the speed perspective you'll be hard pressed to find an app
> that is faster on the sun and the age of the E4500 negates any advantage
> it used to have in reliability. The E4500 doesn't even have redundant
> power :-)

Be careful with your continued assertions.  I/O on the P4 (and the PC platform)
_sucks_ compared to many of these solutions.  PCIe is _not_ the "holy grail"
for a platform that has some severe bottleneck issues in its design, let alone
when we're talking a single processor versus a partial mesh system with a
_real_ "system interconnect."  ;->

Reality:  Even a 200MHz, non-superscalar microcontroller prototype boards
can handle 500MBps+ of storage I/O, but many PC mainboard I/O designs
can_not_.  ;->

> I was giving the E4500 as a comparison because it costs the same.
> Unfortunately we got apps here that outgrow F15K frames - performance
> can't ever be good enough.
> But even if you get a V440 (from integer processing the currently fastest
> cpu Sun has to offer) you're still so much slower when doing compiles.

Once again, I will re-iterate, build times are _not_ a good "server benchmark"
at all.  If they were, then I don't know why _anyone_ would buy Intel --
AMD _roasts_ P4 _over_ 2:1 MHz for MHz.

> Anyway, point I was trying to make is that if anyone points a US-II based
> frame today they are mistaken about its performance and reliability.

I don't think people were asserting "build" time at all, let alone performance
in general.  But there are some advantages to deploying even older SPARC
platforms in some areas.

It's obvious your experience has largely been in "build" or "dynamic web app"
benchmarks.  Please be considerate that it's not the _only_ "performance"
consideration out there.  ;->

> Just the disks in D1000 trays are so much of a headache that you
> wouldn't believe it. And Sun doesn't support booting of EMC on the
> smaller frames - so you need some local attached storage...

There are options around that in various hardware selections.
But yes, Sun does have some stock SAN limitations.



--
Bryan J. Smith   mailto:b.j.smith at ieee.org