CVMFS

Installing and Configuring CVMFS

Step 1: Install CVMFS Client

1. Update the package list and install the CVMFS client:

   sudo apt-get update
   sudo apt-get install cvmfs fuse
   

2. Modify the /etc/fuse.conf and include or uncomment user_allow_other.

Step 2: Configure CVMFS Client

1. Edit the CVMFS configuration file:

   sudo vi /etc/cvmfs/default.local
   

2. Add the following lines to configure the repositories and HTTP proxy:

   CVMFS_REPOSITORIES="unpacked.cern.ch"
   CVMFS_HTTP_PROXY="DIRECT"
   CVMFS_CACHE_BASE="/mnt/scratch/cvmfs/$(hostname)"
   

   • CVMFS_REPOSITORIES: Specifies the CVMFS repositories to be used.
   • CVMFS_HTTP_PROXY: Specifies the HTTP proxy settings. Use "DIRECT" if no proxy is needed.
   • CVMFS_CACHE_BASE: Specifies the base directory for caching files. For our cluster, it is stored in the scratch area.

3. (Optional) Set the cache quota:

   CVMFS_QUOTA_LIMIT=10000  # Cache size in MB (10 GB)
   

Step 3: Create Mount Point

1. Create the mount point directory:

   sudo mkdir -p /cvmfs/unpacked.cern.ch
   sudo chmod 755 /cvmfs/unpacked.cern.ch
   

Step 4: Mount the CVMFS Repository

1. Mount the repository using the CVMFS client:

   sudo cvmfs2 -o allow_other unpacked.cern.ch /cvmfs/unpacked.cern.ch
   

2. In some cases you might need to run:

   sudo mount -t cvmfs unpacked.cern.ch /cvmfs/unpacked.cern.ch
   

Step 5: Verify the Mount

1. Verify that the repository is mounted and accessible:

   ls /cvmfs/unpacked.cern.ch
   

   You should see the contents of the CVMFS repository.

Step 6: (Optional) Configure Automatic Mounting

1. To automatically mount the CVMFS repository at boot time, add an entry to fstab:

   sudo vi /etc/fstab
   

2. Add the following line to the file:

   cvmfs2 /cvmfs fuse defaults,allow_other 0 0
   

3. Save and close the file.

Step 7: Restart CVMFS Client (if needed)

1. If you made changes to the configuration, restart the CVMFS client to apply the changes:

   sudo cvmfs_config reload
   

To load another cvmfs repository

To load any additional cvmfs repository, like grid.cern.ch we need to just modify the file /etc/cvmfs/default.local, like:

CVMFS_REPOSITORIES="unpacked.cern.ch,grid.cern.ch,cms.cern.ch"

and then do cvmfs_config reload.

If this does not work, try with:

sudo mkdir -p /cvmfs/grid.cern.ch
sudo mount -t cvmfs grid.cern.ch /cvmfs/grid.cern.ch

Troubleshooting

• If you encounter issues, check the CVMFS logs for more information:

  sudo cat /var/log/cvmfs/*.log
  

• Ensure that the CVMFS client service is running:

  sudo systemctl status cvmfs
  

• If the service is not found, try starting it manually:

  sudo service cvmfs start
  

By following these steps, you should be able to successfully install and configure CVMFS on your machine.