[Beowulf] OS for 64 bit AMD

Mike Davis jmdavis at mail2.vcu.edu
Sun Apr 3 22:11:17 PDT 2005

What are the good reasons not to have g77 in gcc4? I admit ignorance on 
the subject of gcc4, but g77 is useful to many in the scientific and 
academic communities.

Mike Davis

Joe Landman wrote:

> 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.

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