Access to CERN-EOS from UChicago¶

EOS access from worker nodes

/eos is only mounted on the interactive (login) nodes. To access from worker nodes (e.g. condor jobs), we recommend the use of xrootd such as:

root://eosuser.cern.ch//eos/user/d/dschrute/file.txt

or via xrdcp inside your job:

xrdcp root://eosuser.cern.ch//eos/user/d/dschrute/file.txt .
xrdcp -r root://eosuser.cern.ch//eos/user/d/dschrute/many_files/ .

as long as you export your CERN Kerberos ticket to your HTCondor jobs.

The ways to list, write and read files on CERN EOS, documented here, still work at UChicago.

setup-eos is deprecated

setup-eos has been deprecated in favor of using kinit.

On the Analysis Facility login servers, try the following:

kinit <cern_user>@CERN.CH

as described in CERN Kerberos ticket. To list your files located at /eos/user/d/dschrute/:

ls /eos/user/d/dschrute
# remember to replace "d/dschrute" with your own username at CERN.

To create a new directory at /eos/user/d/dschrute/:

mkdir /eos/user/d/dschrute/new_dir
# remember to replace "d/dschrute" with your own username at CERN.

To copy files from /eos/user/d/dschrute/ to your current directory:

cp /eos/user/d/dschrute/file.txt .
# use `cp -r` if you need to copy a directory

To copy files from /eos/user/d/dschrute/ to any path within your profile:

cp /eos/user/d/dschrute/file.txt  $HOME/codingx/ # eg: /home/dschrute/codingx/
# use `cp -r` if you need to copy a directory

CERN Kerberos ticket¶

You can obtain and cache a CERN Kerberos ticket (this is also required for the way of using ssh-tunnel below) by doing:

CERN.CH must be uppercase

Please notice that the domain CERN.CH must be in UPPERCASE.

kinit <name_at_CERN>@CERN.CH

List your ticket:

klist

Before running the previous command kinit <name_at_CERN>@CERN.CH, pass your CERN Kerberos ticket to the batch machines:

export KRB5CCNAME=$HOME/krb5cc_`id -u` # this defines the environment variable `KRB5CCNAME`

Then add the environment variable KRB5CCNAME to your condor batch job, e.g.:

...
environment = <parameter_list>
...
x509userproxy  = $ENV(X509_USER_PROXY) # this adds KRB5CCNAME to your condor batch job.