SERVICE RISK: The Bessemer HPC cluster will be at risk from 9am on July 15th until 5pm on July 19th 2024

For further detail, please click this link.


The ShARC HPC cluster was decommissioned on the 30th of November 2023 at 17:00. It is no longer possible for users to access that cluster.


The Cooperative Computing Tools (cctools) contains Parrot, Chirp, Makeflow, Work Queue, SAND, and other software.

Interactive Usage

After connecting to the cluster (see Establishing a SSH connection), start an interactive session with the qrsh or qrshx command.

The default version of cctools is made available with the command

module load apps/cctools

Alternatively, you can explicitly load a specific version using:

module load apps/cctools/7.0.14/binary

Accessing CernVM-FS

parrot_run provided by cctools can be used to provide access to CernVM-FS

e.g. to access the Atlas CernVM-FS repo

parrot_run bash

ls /cvmfs/

LibCvmfs version 2.4, revision 25

ATLASLocalRootBase  benchmarks  conditions  containers  dev  images  sw  tools

The environment variable PARROT_CVMFS_ALIEN_CACHE is used to specify the location for the CVMFS cache.

By default the cctools module will set PARROT_CVMFS_ALIEN_CACHE to your /data directory. You can override this behavior by setting PARROT_CVMFS_ALIEN_CACHE to another location.

The environment variable PARROT_CVMFS_REPO can be used to add other repositories.

For more info on using the parrot connector see CernVM-FS documentation

Installation notes

These are primarily for administrators of the system.

cctools 7.0.14

  1. Download the cctools tarball (cctools-7.0.14-x86_64-centos7.tar.gz) from CCL.

  2. Save this file to /usr/local/media/cctools/7.0.14/

  3. Install cctools using this script

  4. Install this modulefile as /usr/local/modulefiles/apps/cctools/7.0.14/binary