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In this issue, we offer users advice on how to migrate their configuration files to FC3, on how to arrange accounts for visitors and how to help manage the load on the mail server.
We also remind teaching staff to make sure that Computing Support is notified of computing requirements for teaching next session's courses, introduce new arrivals in Buccleuch Place and explain how your DICE machine keeps track of time.
Finally we present users Users Hints and Tips for other users
There are a number of applications in DICE (particularly KDE and gnome) which only support forward migration of configuration files. i.e. once you have logged into an FC3 DICE machine you will find that various applications will be unhappy or break if you later log into a RH9 DICE machine.
Unfortunately there is no clean way to deal with this, particularly given that we would ideally like a solution which would
We have produced a bash script:
initdots
which will, for a limited set of
configuration (dot)files, create platform specific dotfiles in
directories under a directory, ~/.DotFiles, in the user's home directory.
The script then creates a link from the original configuration file via
an amd map to the platform specific configuration file, so that when you
come to run the application it will use the correct configuration file
for the version of DICE you are logged into.
This means that for example, where before you had a ~/.mailcap file,
under the new system you will have:
~/.DotFiles/RH9/.mailcap
~/.DotFiles/FC3/.mailcap
~/.DotFiles/SOL9/.mailcap
~/.mailcap itself will be redirected to whichever of these three files
matches the platform of the machine you are currently logged into.
Note that any changes you make to, for example, ~/.mailcap while logged into a RH9 host
will not be automatically reflected in changes to the FC3 or Solaris versions of the file.
This script should be run once before logging into a FC3 host. It will be available on RH9 machines when we ship FC3 hosts.
A second script will be run at login to verify and if necessary re-create the dotfile links.
The full gory details are given on the FC3 Website for those interested in the engineering behind the magic.
/var/lcfg/conf/platspecdots.conf e.g.
#Generated file do not edit DOTS=".cpan .esdauth .gconf .gconfd .gnome .gnome2 .gnome2_private .gnome-desktop .gtkrc-1.2-gnomec .gtkrc.mime .ICEauthority .mailcap .mime.types .mcop .mcoprc .metacity .openoffice .qt " DOTSCLEAN=".kde .gnome2 .gnome2_private .gconf .gconfd .nautilus .gtkrc-1.2-gnomec .gtkrc.mime"
The files listed in DOTS will be copied to all the platform specific
directories under ~/.DotFiles.
The DOTSCLEAN variable lists the files where it's better to start with a
clean configuration rather than have the application upgrade the
configuration files. In this case the bash startup script will copy the
current files into ~/.DotFiles/RH9 and create empty files or directories
in the ~/.DotFiles/FC3 directory. Files listed in DOTSCLEAN will
override duplicates in DOTS.
Individual users can add or remove individual configuration files being
handled by platspecdots by creating ~/.platspecdotsrc and adding files
to the following variables appropriately.
~/.noplatspecdots file
in which case the script will do nothing.
Of the flats in 5BP, five are now occupied. 5BP-4L has housed Axiope Limited for some time - it's a University spin-off company which provides "investigator-oriented software for scientific data integration and collaboration" (for more info, see http://www.axiope.com/aboutus.html
The flat below (5BP-3L) is home to the newest arrivals - the ITI Life Sciences Text Mining Project, in which University staff are collaborating with Cognia EU Ltd (a subsidiary of US-based biological and chemical information management company Cognia which, amongst other things, "develops and distributes information solutions for biotechnology companies" (for more info, see http://www.cognia.com/corporate_news/news_ititxm03-15-05.htm
The Text Mining Project consists of a three-year programme to research and develop "text mining". Based on Natural Language Processing (NLP), text mining allows the detection of meaningful patterns in huge bodies of written text. The School of Informatics, which has significant expertise in NLP, will lead this development of NLP techniques. At the moment, there are eight people working for Cognia EU, and five Informatics staff working in either a full or part time capacity on the project. One more Cognia employee, and five more Informatics staff, will join them shortly and will be working together in the same location.
Cognia staff have their own computing support arrangements, organised by Slawomir Pol. Informatics staff working in this project are continuing to obtain support through Informatics.
The flat below THAT (5BP-2L) is occupied by CSTR, who moved from 1BP a while ago - they've also expanded into the flats opposite (5BP-2R & 5BP-3R). The old CogSci Coffee Room has now, alas, fallen prey to the search for ever-more offices, and its role has been taken on by the CSTR Coffee Room in 5BP-2L so, hopefully, allowing more cross-fertilising coffee conversations.
Julieta Pineda and Roger Burroughes
Every time your mail client starts (and ends) a session with the mail server, the mail server has to scan in (and out) your entire mailbox. With some people now having mailboxes in excess of 100MB, and a few with considerably more, the time taken for the server to read that data in and out increases. If it was just one person accessing the server then it wouldn't be a problem: but there are over 400 active members of staff and visitors using the mail service.
With this in mind, a Good Practices Guide has been drawn up which everyone should read. This will tell you what you can do to reduce your load on the mail service, thus benefiting everyone. The basic message is to reduce the size of your mail folders. The IMP web interface has been modified to show you how much space your folders are using.
We on the mail team will continue to look at what hardware changes we can make to increase the performance of the disk I/O. However this will cause disruption to the service should we need to replace/reconfigure hardware.
Finally, one other incident that has happened recently may affect some Mac OS users.
It appears that a bug in the latest upgrade to Mac OS X's mail client may cause the client to repeatedly fetch the same message
from the mail server while applying local filters. This will drive up the load on the mail server, until the user interrupts
their mail program.
The current status of known software requirements for courses is now recorded fully on the web pages linked from http://www.dice.inf.ed.ac.uk/teaching/.
All teaching staff should check the software requirements for their course(s) there and mail teaching-support-group@inf of any changes as soon as possible. Once the software is installed it is the course organiser's responsibilty to ensure that the software is working to their satisfaction on the new operating system.
As decided at Teaching Committee, priority in porting or making software available will be given to those pieces of software required for the greatest number of students (counting all courses using that software).
For a number of years now we have made use of remote timeservers, located around the UK and in the rest of Europe and the USA, to synchronise a local network of timeservers, to which all the rest of our managed machines are synchronised in their turn. This has worked pretty well on the whole, but network glitches and problems at the remote sites have resulted in unreliable timekeeping on occasion.
In order to improve timekeeping and reduce our dependence on remote servers, we have recently installed two radio-controlled clocks. The first of these uses the MSF timecode transmitted from Rugby. This gives quite reasonable accuracy, considering the low cost of the receiver, but can be affected by electrical noise and is in any case subject to MSF's not-infrequent outages. We have sited this in one of the JCMB offices, as far from any interference sources as we can get.
The other clock is from Trimble's GPS-based range, and is located in the roof of the IPAB area (at 55.92188N, 3.17113W and 83.1m above MSL, OSGB datum). The receiver usually tracks around five or six satellites, and the fact that it is not moving allows it to calculate UTC timestamps to an accuracy of a few tens of nanoseconds. Needless to say, that level of precision has been somewhat diluted by the time the clients have synchronised themselves to the server to which the clock is attached, but an accuracy of a few milliseconds should still be entirely feasible. (The timeserver to which the clock is attached is generally now accurate to within a few tens of microseconds.)
For robustness we are, of course, maintaining our existing associations with the the remote timeservers which we were using previously. These provide a useful sanity-check for our local clocks, as well as giving additional primary synchronisation sources, against the case where both MSF and GPS might be unavailable for some reason.
All DICE managed machines are configured to synchronise themselves to
our network of timeservers.
Users of self-managed machines within the Informatics network
who wish to synchronise their clocks should configure their ntp daemons to
use ntp0.inf.ed.ac.uk, ntp1.inf, ntp2.inf
and ntp3.inf as servers. Outside Informatics,
extntp0.inf and extntp1.inf should be used instead,
as our principal timeservers have been firewalled to help
maintain their integrity.
Incidentally, any managed machines whose clocks are more than a second or so adrift of UTC should be reported as faulty.
There is now a revised system in place for procuring visitor UUNs and subsequent account creation. The May edition of BITs contained an article on the Visitor Registration Service which should be used to create a Universal Username (UUN) for all visitors to the University who require access to any EUCS service.
Your visitor will then be able to register with the EASE authentication service and use the EASE credentials to register for the Wireless service. The University has therefore been decided to phase out the mechanism for authorised administrators to create temporary accounts from Monday 18th July. Until then, no new temporary account will have a duration longer than 7 days and all existing temporary accounts will be set to expire at midday on Monday 18th July.
More on the Visitor Registration Scheme can be found at: http://www.visitor-registration.ed.ac.uk/scheme/introduction.htm
If your visitor is going to need access to any of our resources, then a central University account needs to be created first. Only then can support staff at Informatics create a DICE account for them. A DICE account is needed even if the visitor is using a centrally managed Windows machine.
Please ensure that you give as much notice as possible about visitors. None of the steps above take particularly long but guidelines agreed by Service Managers indicate that a 24 hour turn around for the DICE account creation is acceptable. More information on Computing Guidelines and Policies can be found on the system pages.
Windows users will find that the most recent batch of updates include some which Microsoft categorise as "critical". It is highly recommended that these be applied as soon as possible, as there are believed to be worms and viruses under development to exploit the flaws which the updates patch.
Users of other systems should not be complacent either, as there is usually a steady stream of updates being announced on the various distributions' mailing lists.
This is particularly important for laptop users, who may inadvertently pick up a virus at a remote site and then later bring it back home to infect machines on the Informatics network.
Ultimately, any self-managed machines which cause disruption to the Informatics network or affect other users' work may be blocked from access until the problem is fixed.
ctrl+alt+esc and a skull and crossbones
icon will appear.
$ ledit ocaml
$ cat my_file | awk "{ s+=$2 } END {print s}"
#!/bin/sh
[ -n "$1" ] || (echo "usage: $0 <col> [field_separator]" && exit 1)
[ -n "$2" ] && f="BEGIN {FS=\"$2\"}"
awk "$f { s+=\$$1 } END {print s}"
For instance, the command
$ sum.sh 2 " " < my_filewill add the numbers in column 2 of my_file using tab as field separator.
In general
sum.sh col [fs]
will then add the numbers column _col_ (the first column is 1) of the
lines of stardard input using _fs_ as field separator
(optional argument, by default non-newline whitespace, but can be any regular expression;
watch out: single space is *not* single space, see FS in the awk manual).
control j.
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