The IHEP server (lxlogin)

Within BESIII, most analysis tasks are run on a server that is hosted by . The server is also where you will use BOSS. You will need to apply for an IHEP computing account to be able to log in.

Accessing the server

The IHEP server runs on AlmaLinux9. The server can be accessed through SSH using:

ssh -Y USERNAME@lxlogin.ihep.ac.cn

where USERNAME is your IHEP computing cluster account. The option -Y is optional and ensures X11 forwarding, allowing you to open graphical applications from the server.

Warning

The computing cluster account is different from your IHEP account name. It can be found by logging in to login.ihep.ac.cn and clicking on your name. The account name is listed under “IHEP computing cluster account”.

To simplify the login process, you can first create the ~/.ssh/cm/ directory via

mkdir -p ~/.ssh/cm

and then add the following lines to your ~/.ssh/config file:

Host ihep
  HostName lxlogin.ihep.ac.cn
Match host beslogin.ihep.ac.cn,lxlogin.ihep.ac.cn
  ControlMaster auto
  ControlPath ~/.ssh/cm/%C.sock
  ControlPersist 10m
  PreferredAuthentications password
1  User USERNAME
1
Again, USERNAME should be replaced with your IHEP computing cluster account name.
Note

If you don’t like having to enter your password every time you log in, have a look at the section Key generation for SSH.

In Windows, there are some nice tools that allow you to access the server. First of all, to be able to use SSH, use will either have to use PuTTY or more extensive software like Xmanager. You can also just search for some Linux terminals for Windows. In addition, have a look at the (S)FTP client WinSCP. It allows you to easily navigate the file structure of the IHEP server and to quickly transfer―even synchronize―files up and down to your own computer.

Note

Once in the server, you can switch to other Linux versions using hep_container. In order to do this, you need to add it to your PATH variable by running

export PATH=/cvmfs/container.ihep.ac.cn/bin/:$PATH

Once you have done this, you can switch to the version of your choice by running

hep_container shell CentOS7

where shell can be replaced with your shell of choice and CentOS7 with your distribution of choice. The available distribution versions can be found by running:

hep_container images

Important data paths

Some other important directories for the BESIII Collaboration are the following:

  • BOSS Software directory
    • /cvmfs/bes3.ihep.ac.cn/bes3sw/Boss (also referred to with $BesArea)
  • Raw data files
    • /bes3fs/offline/data/raw
    • /besfs5/offline/data/randomtrg (random trigger data)
  • Reconstructed data sets
    • /besfs3/offline/data/
    • /besfs/offline/data/ (older versions)
  • Reconstructed Monte Carlo sets (latest version available is 6.6.4):
    • /besfs2/offline/data/664-1/jpsi/09mc/dst (2009; 225M)
    • /besfs2/offline/data/664-1/jpsi/12mc/dst (2012; 200M)
    • /besfs2/offline/data/664-1/jpsi/12mc/grid/dst (2012; 800M)
    • (no reconstructed MC samples available yet for 2018)

These directories will be important later in this ‘tutorial’.

Note

For the latest data file locations, see this page.

Changing to your preferred shell

By default, the shell for your user account is set to tcsh. You can apply for other shells like bash, csh, and zsh through ccsuser.ihep.ac.cn and then clicking “Apply to change default shell”.