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slides “Project and User Account”

Required to log into VSC is at first an account at VSC. Therefore you or your group leader has to have a project on VSC which can be applied for at our service website: https://vsc.ac.at//access/project-application/ https://service.vsc.ac.at

One project can be associated with the group of users who are working in that project, each of them having her or his own user account. Due to two factor identication an account does not only need a password but also a mobile phone number in order to receive the second factor which is a short code sent by SMS. If you forget your VSC password or if your phone number changes, your project manager can reset that.

The next prerequisite to login is that you are physically or virtually via VPN in the university network. For problems with your VPN, please contact the IT support of your institution.

Last but not least, you need some kind of terminal program: e.g.,

What you see in the sketch is the very simplified view on the cluster. You login through the login nodes and from there you can send your jobs to the ompute nodes. We will show you in this course that you can connect as well to the login nodes and as a further step also to the compute nodes.

slide 2 “Project and User Account”

now we will focus on the first part, i.e., connecting to the login nodes

slide 1 “Connecting to VSC”

VSC-3 has 5 login nodes, called l31, l32, …, l35, VSC-4 has 10, called l40, …, l48, l49. Login to <html><me></html>@vsc3.vsc.ac.at or <html><me></html>@vsc4.vsc.ac.at will put you to one of the login nodes by round robin manner. (<html><me></html> will be used in the slides as short form for <html><username></html>.)

slide 2 “Connecting to VSC”

However, you may have reason to login to a dedicated login server, then specify the name of the namely server.

slide 3 “Connecting to VSC”

DEMO show that one in a terminal and explain

.bashrc

In the .bashrc file you can set personal preferences that make your life easier, defining aliases for often used commands and so on.

One thing that you should set there are the language settings. If you come from a system whose language settings are different from that of the VSC operating system you will not be able to compile etc. The language settings of your local operating system are most probably adopted in an ssh connection. That happens, if you find “SendEnv LANG LC_*” in the /etc/ssh/ssh_config on your local system.

local: example (my OSX):

LANG=""
LC_CTYPE="UTF-8"
LC_ALL=

VSC:

LC_CTYPE=en_US.UTF-8
LC_ALL=en_US.UTF-8

Way out: either you comment this one line “SendEnv LANG LC_*” in your /etc/ssh/ssh_config or you add these two lines in the .bashrc in your VSC-3 oder VSC-4 home directory:

export LC_CTYPE=en_US.UTF-8
export LC_ALL=en_US.UTF-8

in general: Language settings

A locale is a set of environmental variables that defines the language, country, and character encoding settings (or any other special variant preferences) for your applications and shell session on a Linux system. These environmental variables are used by system libraries and locale-aware applications on the system.

Locale affects things such as the time/date format, the first day of the week, numbers, currency and many other values formatted in accordance with the language or region/country you set on a Linux system.

in /etc/ssh/ssh_config there is a command

SendEnv LANG LC_*

which means that in ssh connections the local environment is taken to the remote machine. If that is also the case for your machine then you may get into trouble if the local settings are not equivalent to the remote settings.

slide “again and again”

Although the OTP is valid for … hours, if you need several shells on the cluster at the same time you always need to retype your password.

  • pandoc/introduction-to-vsc/101_notes/notes_v01.txt
  • Last modified: 2020/10/20 08:09
  • by pandoc