My ssh-ed remote account

What is a remote account ?

We call here a remote account an account that you have been given. It has the following features:

A login and a password identify you as the user of that account.
An account is attached to a cluster, so it is known by the cluster frontend and by all the machines in the cluster.
An account allows you to log on any machine of the cluster. Then, you can access to the physical disk of that machine (e.g. the directory /tmp, the /usr/bin directory where all the executable are, etc…)
An account, for example with the logging parker_ptr comes with a mounted disk space, that is allocated to it and that is accessible (i.e. mounted) from any machine of the cluster. Usually, that disk space is accessible in a directory such as /home/parker_ptr, which is the home directory of the account (where you are placed once you are logged).

Ok, let us remember here things about the clusters that we have. We show the access node (where you can ssh from outside and get access to your account), the frontend (which handles booking and allocation).

cluster	kind	ssh access	frontend
kyle	CPU	phome.metz.supelec.fr	slurm1
sarah	CPU	phome.metz.supelec.fr	slurm1
john	CPU	phome.metz.supelec.fr	phome
ic	CPU	phome.metz.supelec.fr	ic10.ic
uSkynet	GPU	ghome.metz.supelec.fr	term2.grid
gpu	GPU	ghome.metz.supelec.fr	slurm2

So for example, to access the kyle CPU cluster from the outside of the school, you can ssh with your account to phome.metz.supelec.fr and, the hostname of the machine scheduling the access to the resources of kyle is slurm1.

How can I use my account ?

Let us suppose that your account is parker_ptr, and that the frontend of the cluster is front.centralesupelec.fr. Having a bash session on the cluster from a bash on your personal computer is done by ssh:

mylogin@mymachine:~$ ssh parker_ptr@front.centralesupelec.fr

And now, you are the user parker_ptr, located on the front end. Quit this with CTRL-D or the exit command.

To transfer files up to your cluster account, you can use scp from a bash running at your personal computer.

mylogin@mymachine:~$ scp -r some-directory parker_ptr@front.centralesupelec.f:~/where-I-want-to-copy
mylogin@mymachine:~$ scp -r parker_ptr@front.centralesupelec.f:~/some-directory where-I-want-to-copy

There exists alternatives like using mounting your remote homedir with sshfs, transferring with rsync, etc…

How can I avoid to enter password every time ?

Whatever the ssh-related command you are doing to communicate with the remote account parker_ptr, you are asked to type the password associated to parker_ptr. This can be annoying… but this can prevent some scripts to work !

So you have to send your public key to parker_ptr so that you can be identified by it.

This is explained in the section SSH Keys for negotiating with servers, do this right now if you haven’t done this yet, and test it (i.e. you should be able to log on an access node without entering password other than your ssh-key password).

And now ?

You have an access to the cluster, configured with ssh correctly, the cscluster script will rely on this to enable you to book machines, release machines, open ssh tunnels… See the Allocation section of this website.

Hervé Frezza-Buet, Jérémy Fix,