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Cluster access

Access to the cluster is made trough an independent virtual machine called frontend(ctcomp2.inv.usc.es). This frontend has very limited resources and it's only purpose is to manage file transfers and job submissions to queues. Code execution is not allowed in this server.

Remote access to the frontend is made with ssh (secure shell). Access credentials are the CITIUS ones. Note: If having problems connecting using the hostname then use the IP address instead: 172.16.242.122.

local$ ssh [-X] -p 1301  citius_user@ctcomp2.inv.usc.es
Password:
ctcomp2$ 

The -X parameter is optional. Connects the X redirection. It is an essential requirement in order to execute programs that need a graphical mode.

File import/export

The cluster's filesystems are independent and are isolated from the CITIUS network so it is necessary to import to the cluster's user space all necessary files to execute our programs (for example, source code or the input files).

An user has the following places available, inside the cluster's filesystem, to place his files:

NO backups are made of the user's $HOME directory.

To import and export the necessary files in and out the cluster the scp command is used. It allows the user to move files between other file systems in the network. Syntax of the scp command is the following:

scp -P 1301 [-r] <source_address> <destination_address>

Argument explanation:

scp command examples in ctcomp2

As an example, several cases of file imports are shown. In this examples it is assumed that the user is user.name and that his workplace is ctXXX.inv.usc.es. The file/directory to be imported is located in ctXXX.inv.usc.es in the /datos/work/ directory and that we want to copy them to the user's working space in the cluster in the directory work in the user's $HOME. If we use scp from inside the cluster after logging in trough ssh:

ct$ scp -P 1301  user.name@ctXXX.inv.usc.es:/datos/work/one.file  ~/work/
ct$ scp -P 1301  -r user.name@ctXXX.inv.usc.es:/datos/work/directory/  ~/work/

Id using scp from our own computer:

local$ scp -P 1301 /datos/work/one.file  user.name@ctcomp2.inv.usc.es:~/work/
local$ scp -P 1301  -r /datos/work/directory/   user.name@ctcomp2.inv.usc.es:~/work/