How can I connect to DESY, Zeuthen from outside or from home?

There's a variety of methods, documented here: http://dv-zeuthen.desy.de/services/remote_login/

What is considered acceptable use of the public login linux systems?

Since these are shared between many users, and are low-end compared to the systems in the batch farm, please only use them for their intended purposes:

Acceptable:

• connecting from outside with ssh and hopping to internal systems

• desktop work (mail, browser, TeX, ...)

• software development

  • building, short test runs (< 5 minutes, at nice level 19)

Not acceptable:

• production runs, test runs longer than 5 minutes or without being nice 19

  • please use the batch farm for those

  • applies to any kind of software (experiment, mathematica, ...)

• anything with huge memory requirements (significant compared to what the system has)

  • again, run these on the batch farm

• transferring/processing larger amounts of data, both internally and from/to the outside

  • for internal transfers, agin the batch farm can be used
  • for transfers, see below

In many of these cases, you should receive an automatic mail pointing out that you're abusing the systems and suggesting alternatives.

I received an automatic mail asserting that I'm abusing a public login linux system. What now?

Do not ignore it.

• If you are abusing it, according to the rules stated above, stop it and use the appropriate alternative. Contact uco for help if you think there is no acceptable alternative to doing it on the pubs.

• If you are not, please contact uco and explain what you did and why you consider it legitimate.

This will allow us to adjust the policies or the abuse detection, or provide an acceptable alternative.

What happens if I keep ignoring these automatic notifications?

Eventually, your account will be added to a list of accounts with usage restrictions. All your processes will be set to nice level 19, have a hard CPU time limit of a few minutes, and may have a hard memory usage limit. The next linux release SL5 will also allow to limit I/O throughput relative to other processes on the system.

These measures do not prevent using these systems the way they're meant to be. They just help to keep them usable for other users as well. They also make it possible again to monitor the systems properly and detect problems with hardware or configuration.

How can I transfer data from/to Storage at DESY, Zeuthen?

• The best method is generally to use our GRID Storage Elements.

• If this is not possible, use the dedicated system transfer.ifh.de and scp. This system is accessible from outside - it has to be because many labs and universities obviously do not offer such a service.

• Do not use the public login linux systems, or you may find your account in the list of those with usage restrictions on them.