[Beowulf] Building new cluster - estimate

[Gerry Creager]

Matt Lawrence wrote:
> On Wed, 6 Aug 2008, Robert G. Brown wrote:
> 
>> On Wed, 6 Aug 2008, Perry E. Metzger wrote:
>>
>> And even on Linux machines, NFS has been, well, "functional" is a good
>> way to describe it.  For its primary original purpose, which is serving
>> home directories or remote mount e.g. binaries in midsize and smaller
>> workstation LANS, it is adequate and has worked well for us for almost
>> ten years (not without some pain, mind you, but with no more pain than
>> anythng else).  For the last five or six years even most of the pain has
>> gone away and things like automounting work most of the time with only
>> rare hangs or stale mount problems (on highly reliable server hardware
>> and with a very reliable network).
> 
> Youngsters these days.....
> 
> I still have painful memories of an environment with too many 
> filesystems cross mounted between workstations and (at the time big) 
> minicomputers. All too often someone would shut down a workstation that 
> was serving a filesystem and everything would crash.  Just like dominos.
> 
> Like I said, a sordid history.

Whiling away my misspent youth at Johnson Space Center's Software 
Technology Branch, while I wasn't an official system administrator (we 
had few "official" sys-admins) I did back-stop them for some functions, 
and had root access.  We had a rather complicated cross-mount system 
requiring carefully timed boot/power-up cycling, lest we spend the whole 
day randomly rebooting things to fix cross-mount dependencies.  No, that 
wasn't by design of the incumbents at the time, but it was so pervasive 
(and big Sun servers capable of taking over the whole fileserver load 
were so expensive relative to our budget) that we fixed these issued a 
little bit at a time.  This was also the era where a run-away ping sweep 
took down a few routers in the US... and elsewhere... when router tables 
filled up.  And, yeah, that originated from my piece of the Branch, too.
-- 
Gerry Creager -- gerry.creager at tamu.edu
Texas Mesonet -- AATLT, Texas A&M University	
Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983
Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843