[Beowulf] OS for 64 bit AMD

Joe Landman landman at scalableinformatics.com
Sun Apr 3 21:44:58 PDT 2005

Hi Bob:

   My main thesis really is that FC-x != FC-(x+1) in terms of core 
interfaces.  As we have read from Toon, gcc4.0 won't have a g77 (for 
good reasons), and FC4 will be using gcc4.0.   gcc4.0 != gcc 3.4.  Of 
course these are not the only changes.  The big issue was the stack size 
change.  That one killed off my wireless driver and wreaked havoc with 
my graphics on my test machine.

Bob Drzyzgula wrote:
> I've been following this discussion, and I just wanted to
> throw in my $0.02 on a couple of points:


>    What is much more important in a true "production"
>    environment is the length of time one can expect to
>    obtain patches for the OS. No "production shop" that

I get the feeling that this is an unwinnable argument.  One person 
(Mark) argues that support patches are effectively a tool to lock you in 
(and if I characterized this wrong Mark, please feel free to correct 
me), and you argue that this is the only reasonable feature of a 
production OS.   I stand by my thesis that a production system is a long 
term stable (interfaces, drivers, ABI) and supportable system, in that 
RHEL3 u5 will not be significantly different than RHEL3 u4, and one 
should not expect broken interfaces or changed stacks, or similar bits 
between these releases.

>    really is running a "production application" is likely
>    to be replacing the OS on anything like the kind of
>    schedule that FC-x -- or even RHEL -- releases come
>    out. They are much more likely to qualify all their
>    applications on a specific OS release, move this new
>    image -- OS + applications -- into production, and run
>    it until there is some compelling reason to change,
>    and this compelling reason can be several years in
>    coming. Even OS patches would only be applied in
>    limited circumstances. These would be (a) to remedy a
>    locally-observed failure mode, (b) to support required
>    application updates, or (c) to address specific security
>    issues. In all cases except in the most severe security
>    problems, such patches would be applied after extensive
>    testing to verify that production activities would not
>    be affected.

Agreed.  This is SOP in most cases.

>    Now, in principal there is no real reason why --
>    vendor support notwithstanding -- a production shop
>    could not be set up to run on e.g. FC-3. However, the
>    disappearance of the official patch stream after a few
>    months would, or at least should, give one pause. Of
>    course there is Fedora Legacy, and one can always
>    patch the RPMs one's self. But it all starts to get
>    pretty tenuous and labor-intensive after a while. By
>    contrast, Red Hat is promising update support for RHEL
>    version for at least five years after release. *This*,
>    not the release cycle, is why production shops -- and
>    their application vendors -- will prefer RHEL over
>    FC-x. It really doesn't (or shouldn't) make a damn
>    bit of difference to a production shop how the OS is
>    characterized: "beta", "proving ground", "enterprise",
>    whatever. What really matters is the promises that are
>    made with respect to out-year support.

The issue over proving ground vs beta vs enterprise was a semantic 
splitting of hairs that I am regretting spending cycles on.   The real 
issue for the application vendors is the cost in the end.  Anything that 
reduces cost is a good thing (longevity of platform, popularity of 
platform, few numbers of platforms).  This is why frequent release cycle 
systems are not targetted, unless there is a compelling business case 
for it.


>    direction. RHEL can suck pretty bad in a research
>    environment, where you are likely to wind up with half
>    of the RH-supplied packages supplemented with your own
>    builds of more recent stuff piling up in /usr/local.

<grimace>  Yup.  The problem is that when you start changing enough 
stuff out, you create yourself a new distribution and you own all the 
headache of this (substantial)

>  * I get a bit frustrated at the hostility toward
>    commercial applications and closed hardware, especially
>    to the extent that it gets directed toward the customers
>    of those products. If there existed an open replacement

agreed.  For some things there are no replacements.


>    The same goes for closed hardware. I don't much
>    care about high-end graphics cards, but storage
>    is a big issue.  I've recently been looking for new
>    storage for a sizable network, and am finding that the
>    option of affordable external, high-speed (FC class)
>    RAID controllers serving up generic, high-speed,
>    high-reliability (e.g. not SATA) disk, has pretty much
>    vanished from the market over the past year or so. As
>    has been mentioned, everyone wants you to use their
>    JBODs, their disk modules, and in some cases their
>    HBAs and closed-source drivers. And they want you to
>    pay dearly for it. I hardly find this acceptable, but

Not going after the SATA vs FC/SCSI point.  There are some out there in 
the "white box" variety.  Storcase, bowsystem, and a few others used to 
have bits like this, though I often hear people talk about only buying 
major brands for storage.   I still have not seen affordable FC.

>    I honestly don't know what else to do except to decide
>    that capacity, throughput, reliability, availability and
>    manageability just aren't that important after all.

They are, but there seems to have been technological shifts.

> --Bob Drzyzgula
> [1] Matlab is actually a poor example for this discussion
> in that, to their credit, Mathworks in fact only
> requires, beyond a 2.4 or 2.6 kernel, a specific glibc
> version. 2.3.2.

Joseph Landman, Ph.D
Founder and CEO
Scalable Informatics LLC,
email: landman at scalableinformatics.com
web  : http://www.scalableinformatics.com
phone: +1 734 786 8423
fax  : +1 734 786 8452
cell : +1 734 612 4615

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