Hello and welcome, I'm Alex and this is a tutorial on how to access EOS from central services LXPLUS or LXBATCH,
and how to use EOS/XRootD commads to access your EOS instance.
First of all, let's see how to access EOS from central services, LXPLUS or LXBATCH.
First of all, you need to be connected to lxplus. Open up your Terminal and type in the ssh command.
LXPLUS and LXBATCH notes are now set up to let you see your EOS files as a file system.
To see the EOS file systems that are available, type the LS command.
Go to the EOS file system to which you have access by the cd command.
You can "ls", "cp", "cat", "emacs" your files the usual way.
The next part of this video will cover using the specialised client and EOS/XRootD commands to access your EOS instance.
This used for
Now that you are connected to lxplus, you need to set your environment, you will have to define the EOS instance you want to use.
Type in the export command. If you are affiliated to an experiment such as CMS, you should insert your experiment intead of “user” at all times. Like this.
If you are affiliated to an experiment other than an LHC experiment, such as AMS for example, this is the correct instance to use.
After having set up our environment, we can proceed by creating a subdirectory on EOS. Type in the make directory command.
Now you should make sure that you have a local file available in your current directory, because we are going to upload this file to EOS.
For the sake of this tutorial, let's create one using the "touch" command
And check if the file is there.
Let’s now see how to upload a file to EOS.
Once you have the local file, you can proceed by copying this file to your EOS directory, by using the x root d copy command:
Now a file called “eos1.txt” has been uploaded to your EOS directory, and you can check for the presence of this file.
Now we can download the file back to our directory by using the x root d copy command:
And finally, you can check for the file’s presence, and see that it’s actually there.
Thank you for your attention, and see you in the next tutorial!