Domain: unitn.it
Stories and comments across the archive that link to unitn.it.
Comments · 5
-
paper
I think this is described in more detail in a paper that was presented at ijcai 07 this morning. It was fascinating. here is the paper and http://www.eml-research.de/english/homes/strube/p
a pers/aaai06.pdf is another paper on the same subject -
Re:For the grace of Bicycles, go I.
Easy while your young, but it gets progressively harder. Especially when you start adding up all the things that I've had to deal with on a regular basis
That's why I included the "unless you're old" disclaimer. As for the other things you mention:
From drivers (hit by a car once. many close calls)
No difference bewteen a bicycle and a scooter.
From snow (drifts, and mounds. Love it when the plow throws it up on the sidewalk) and ice (very fun)
Again, no difference, except you may be going faster on a scooter, so you'll fall harder.
Flat tires, and the occasional (other part failing, or just wearing out).
Again, the same as with a bicycle, only a bicycle is cheaper to fix. If you have problems with flats on a bicycle, get some tougher tires. Some are practically impervious to any kind of damage, although a little slower rolling than the more fragile ones.
I'll give you the hot and sweaty complaints, if you live in that kind of a climate in hilly terrain. But otherwise, just go easy. I know people who ride 20 miles each way in summer, in shirt-and-tie work clothes, w/ no problems. The rest of your complaints may be covered by the "old" disclaimer. Regarding that, though -- look at the kind of riding many "old" people are still doing:
http://www-math.science.unitn.it/Bike/Countries/Eu rope/Tour_Reports/Tour_of_the_Alps/
Jobst is in his late 60s, maybe 70 by now.
-
I didn't read it.
I haven't read this book, and I'm not sure I want too, because it seems to be overkill. Bicyclists in search of a practical, down-to-earth analysis of the bike might check out the prodigious writings of Jobst Brandt, a mechanical engineer and avid touring rider. Brandt eschews quantum mechanics and other irrelevancies and instead analyzes and explains the real problems of bicycles. Most notably, Brandt published The Bicycle Wheel, the definitive text on the function, response, and building of spoked wheels. I used it to select parts for and to build my current wheels and let me tell you, building your first set of bike wheels is even more interesting than building your first PC.
Brandt is a tourer of some note. His Alpine and Sierra Nevada tours are legendary and have inspired a lot of cyclists.
You can access and search Brandt's writings via USENET: try looking at rec.bicycles.tech. -
help these people!
... make a new homepage. Yikes! My God they should do something about it.
Seems they have. There is a no-background-image version.
I don't want to troll, but even setting (in IE, mind you) the text size to "largest", I can still hardly read the links. For the love of Christ, red text on blue background? Argh! -
Some Strategies -- Debian, NIS, automated installsWith any kind of roll out of this size you are going to do massive customization. What defines
which distribution you wish to use is which one
is easiest to customize. I have found Debian the easiest to customize to my needs. In most large environments, people don't upgrade machines, they wipe them out and migrate their server data. Debian gives you the choice of upgrading machines.
The real power of debian, is that you can customize one users machine and those customizations will continue across upgrades. Not everyone needs dia, but some subset of people do and they have dia and when the upgrade they still have dia and you don't have to do anything. That is powerfull and usefull. Yes you have to login to someones machine and give them dia the first time.
If you use debian you need dzinstall and you will need to customize the base install.
Another important strategy that has not been
discussed is how do you break this down to groups.
Identify groups of dependent people. The accounting department is all dependent on everyone else there so they should be made a unit. Give them their own server. I would aim for 1 server for every 20-100 users. Those users should be able to function with their server even if the "centralized" servers go down.
each "departmental" server should be backed up, should have a "network drive", a "name server", an "account server", a "network server", "OS Server", "print server"
NFS server
NIS slave
DHCP server
DNS server
Web server (Intranet)
LPD
should server as an apt server or as an rpm server
The machine configuration for the department should also live on your central server and should be pushed out to each department using rsync. But by distributing the neccesary services you reduce this risk of a catastrophic failure hitting all users.
NIS/NFS
NIS/NFS security I know it is impossible but they are very convienient and there are some precaustions you can take.
NFS -
users do not have root on NFS clients. IF they do they can be any user on the system.
you keep a static arp table for IP address and you
use static DHCP for clients. And you list every
client that is allowed to connect to your NFS server. Yes this can still be hacked!!!! but someone cannot just bring in a laptop and full control over your users files. Its keeps accidents from happening.
NIS
enforce use of good passwds. this is done by configuring the passwd program.
Make sure you have slave NIS servers!!!! Set the local slave to be the default NIS server for clients.
Don't use broadcast NIS, set the NIS server on each client. Yes someone can still spoof your NIS server, do not let the NIS from the outside internet in. It is worth it to trust your users, becuase it makes your computing environment better and you can trace down who caused problems and get them fired.
Automated Installs.
2500 user machines
assume 50 departmental server and 5 back end master servers.
Buy new equipment and do the master servers correctly.
Replication Strategy.
Make sure you can produce a departmental server from a blank box in 2 hours. Make sure anyone who can read instructions can produce a departmental server in 2 hours. And hopefully that won't be two hours of interactive time.
Given a departmental server, make sure you can build a new desktop from a blank machine in one hour. If cannot you have problems with your automation and your network fix!
USE SOURCE CONTROL all system infromation should be in source control! From the very beginning keep your management scripts, your NIS source files, your deployment descripters in Source control, I reccomend CVS! This will make your life easier.
DESKTOP
as for a desktop, I like windowmaker, I think it is very obvious for beginning users.
WP is substantially lighter than Star Office, and is fairly feature complete. Star office will be a pig, try it out, some users will require it as it is the most feature complete office swuite available on linux. (NOTE DO NOT INSTALL star office so it is user writable, even if there is just one user per machine install it as a net install "setup /net" otherwise it lets users corrupt it) Applixware is clean, fast, stable has
strange user interface, and doesn't have the feature count that many people want. And what you see on the screen and what you see on the printer tend to be pretty far off.
I would reccomend avoiding net storage for applications and even all user data. Hard drives are cheap. It makes users less reliant on the network for performance issues. It also makes users for more in control at their workstation and it allows you to customize a workstation to an individuals tastes. (this is why debian is great, you get both customizations and easy upgrades). From a computing efficiency standard this does not make sense the net-slave computers are better. From an employee productivity standard this makes lots of sense.
When setting this up script everything, make sure
the that someone other than the person who solved the problem tries it and can do it.
This is a lot of work and requires formalizing a lot of things. I would reccomend start trying to build the departmental server. The build the things to build the departmental server, destroy it and verify that it can be automaticall built by someone else, using information stored in source control. After that then start doing the end user workstations.
Good LUCK! if you found any of these thoughts usefull do email me.