ARSC T3E Users' Newsletter 142, May 15, 1998

Year 2000

[ This is the first in an occasional series. Please send us your y2k anecdotes and lessons, so that we may all participate more fully in this experience. Anonymity assured. :-]

UNICOS/mk 2.0.2 complies with the Year 2000 date standards as defined by the X/Open standard (ARSC installed UNICOS/mk 2.0.2 on yukon on Feb, 24 1998). See:

http://www.rdg.opengroup.org/public/tech/base/year2000.html

Here's SGI's definition of Year 2000 Compliance, taken from:

http://www.sgi.com/Technology/year2000 :

As more companies begin to address the Year 2000 problem, many of them are releasing their own definitions of Year 2000 compliance. Silicon Graphics' definition is intended to address and encompass concerns that have been raised by our customers.

Silicon Graphics defines a product to be Year 2000 compliant if it does not produce errors or experience loss in functionality as a result of the transition to the Year 2000.* Silicon Graphics is testing its current and new products for compliance based on this definition.

* Errors means errors in date-related data or calculations and the input and output of dates (including leap days), before and after January 1, 2000, through 2037. Functionality means the processing of date-related data, including maintenance of a consistent relationship with the real (external) time and date. In addition, a Year 2000 compliant product will define a specific and unambiguous interpretation of two digit representations of the year, following the guidelines for UNIX recommended by The Open Group. This Year 2000 compliance statement is not a product warranty. Silicon Graphics Year 2000 compliant products are provided under the standard Silicon Graphics terms and conditions of sale, license and support.

For self-written software, Cray recommends the `69' Rule:

Cray Research recommends that customers apply the `69'-rule to their two-digit ASCII (YY) dates. This rule interprets years greater than `69' (that is, 1969 -- the UNIX clock begin ticking January 1, 1970) as 19YY. Years less than `69' will be interpreted as 20YY.

Cray Research further recommends that customers implement a four-digit YYYY policy to be applied to all newly-created date fields.

Here's a good one, taken from the X/Open page listed above:

Many COBOL programmers have tended to mix data and control information, usually to save space in databases. In particular, for example, the "year" field would be a date if numerically larger than say 20, and a command or EOF flag if from 0 to 19. So, rollover will potentially cause great excitement for some database users, much more than wrong dates.

"Maya" Seminar (Next Monday at ARSC)


Monday May 18, 1998           9-12am and 2-5pm,           Butrovich 107

Maya is a comprehensive animation package from Alias/Wavefront, which incorporates nurbs (non-uniform rational B-spline) modeling, and soft and hard body dynamics with particle effects. The class will introduce users to the customizable interface and the node-based struct- ure of maya objects. We will animate a bouncing ball with personality. The ball will squash and splash virtual water. The material to be pre- sented is the first eight hours of the five-day "Introducton to Maya" course, taught by Alias/Wavefront. Maya will be offered in a regular class starting this fall. The instructor will be Bill Brody.

Please register for the one-day seminar by calling 474-1895.

"ImmersaDesk" Seminar (Next Thursday at ARSC)


Thursday May 21, 1998             2pm                      Butrovich 109

An ImmersaDesk, a new, state-of-the-art visual display system, has been installed at the Arctic Region Supercomputing Center (ARSC) in Butrovich. This system allows interactive, immersive data exploration using large- screen, 3-dimensional display technology. The ImmersaDesk provides new opportunities for impressive presentations and data visualization. Dr. Chris Hartman, who holds a joint appointment with ARSC and the UAF Mathematical Sciences Department, will teach a computer science course on the ImmersaDesk in the fall.

ARSC will present a one-hour seminar, "Introducing The ImmersaDesk", in Butrovich 109. This seminar will demonstrate the power of the Immersa- Desk and the impact it can have on your research. Please plan to attend! Training for the ImmersaDesk will be available at a later date.

DMF Services on Yukon

When yukon is rebooted after the site-wide facility downtime scheduled for this Sunday, the /u1, /u2 and /tmp filesystems will be under control of DMF, Cray's data migration facility.

Data migration occurs when the physical filesystem becomes nearly full. Large or old files are transferred off disk; any access returns the file to disk. All transfers are automatic and no special actions are required by the user. It takes between 20 seconds and several minutes to return a migrated file to disk (depending on its size and the system load).

Migrated files are listed in the normal directory structure, and are identified by an m in the first field of ls -l output. E.g.:


     yukon% ls -l
     mrw-------   1 user group    204136541 Mar 27  1997 big_file.tar.Z

Users can force the migration of files to/from disk using dmput/dmget. Given the delay in retrieving a migrated file, NQS users may want to dmget needed files at the beginning of their qsub scripts (it does no harm to execute dmget on a file which has not actually been migrated).

Yukon Disk Quotas and DMF

Once DMF is active, quotas on Yukon will be applied according to the same policies that have been in place on chilkoot since cut-over. Quotas will be applied to the /u1, /u2, and /tmp file systems as follows:


   /u1 and /u2:   Quotas apply to data physically on disk, only. 
                  They do  not apply to data which have been 
                  migrated off-line.

   /tmp:          Quotas apply to the data aggregate.  That is, 
                  files that remain on disk AND migrated files 
                  are counted and the aggregate storage volume 
                  is measured against the user's quota.

All users have the same quota:


   /u1 and /u2:   10 GBytes (on-line, unmigrated files, only)

   /tmp:          10 GBytes (aggregate)

On /u1 or /u2, if you are running out of quota, you might want to force the migration of files off-line. The command:


   dmput -r -w filename

would move the file, filename, off disk. (See man pages for details.)

On /tmp, this method would not help stay under quota because, as described above, on /tmp, both migrated and unmigrated files are under quota control.

Note: CRL should still be used for keeping archive copies of important data and for long term storage. CRL access is from chilkoot, only.

SGI/Cray On-Line Manuals

Hypertext manuals written by SGI/Cray (often termed "Dynaweb" manuals) are now available to your web browser via ARSC's online server:

http://www.arsc.edu:40/

Many of the documents are proprietary; thus, they are password protected. ARSC users may obtain the generic login and password by typing:


  news documents

on any ARSC system.

At many sites, this suite of SGI/Cray documentation is served by a "dynaweb" server. The dynaweb server, however, is delivered as a binary, with unknown security control. Thus, ARSC's webmaster chose to add a port to our apache web server in order to serve the "dynaweb" manuals. This gives us known security and, an added advantage, only one server to maintain.

The "xhelp" X app. provides a different set of SGI/Cray hypertext documents. xhelp runs under UNICOS and U/mk, and documents X tools, such as:

  • totalview
  • apprentice
  • xbrowse

ARSC users: if you have any problems or questions concerning Cray's online manuals, please contact consult@arsc.edu.

Quick-Tip Q & A


A: {{ Can "vi" insert a "
" character into the same column over a
      specific range of rows?  Even if some of the rows are empty?  Or
      short? }}

    vi can do anything, of course... 
  
    Assume you want to insert the "
" in column 26, in the range of
    rows between 10 and 30.  You need to execute these three ed
    commands:

:10,30v/.\{25\}/s/$/                         /
:10,30s/.\{25\}/&
/
:10,30s/ *$//

    What does it do?  
    1) In the row range 10-30, appends 25 spaces to any line shorter 
       than 25 characters.

    2) Uses the & replacement character to replace the first 25
       characters of each line with the same 25 characters, and then 
       adds the "
"

    3) Removes all trailing spaces which might have been added in 1).



    Here's one way to execute these three command lines.
    1) Copy them to the very end of the file.

    2) Move the cursor back up to first of these three lines:
G2k

    3) Yank the three lines into some named buffer. For instance, 
       buffer "t":
"ty3y

    4) Execute the commands in the buffer using the @ command. 
       For instance:
@t

    5) Remove the three command lines from the file, and you're done:
G2kdG

    One problem: this solution deletes all trailing spaces from all
    rows between 10 and 30, even if they existed before the operation.



Q: I'm going to CUG in Stuttgart, and then I'm going on vacation.
   (And, no, I'm NOT taking my laptop!)

   How do you Unix wizards trick e-mail into sending those automatic,
   "Don't bother me, I'm at Eurodisney," messages?

[ Answers, questions, and tips graciously accepted. ]


Current Editors:
Ed Kornkven ARSC HPC Specialist ph: 907-450-8669
Kate Hedstrom ARSC Oceanographic Specialist ph: 907-450-8678
Arctic Region Supercomputing Center
University of Alaska Fairbanks
PO Box 756020
Fairbanks AK 99775-6020
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