Transfer Data Inside ZIH Systems with Datamover

With the Datamover, we provide a special data transfer machine for transferring data with best transfer speed between the filesystems of ZIH systems. The Datamover machine is not accessible through SSH as it is dedicated to data transfers. To move or copy files from one filesystem to another filesystem, you have to use the following commands:

• dtcp, dtls, dtmv, dtrm, dtrsync, dttar, and dtwget

These commands submit a batch job to the data transfer machines performing the selected command. Except the following options their syntax is the very same as the well-known shell commands without the prefix dt.

Additional Option	Description
--account=ACCOUNT	Assign data transfer job to specified account.
--blocking	Do not return until the data transfer job is complete. (default for dtls)
--time=TIME	Job time limit (default: 18 h).

Managing Transfer Jobs

There are the commands dtinfo, dtqueue, dtq, and dtcancel to manage your transfer commands and jobs.

• dtinfo shows information about the nodes of the data transfer machine (like sinfo).
• dtqueue and dtq show all your data transfer jobs (like squeue --me).
• dtcancel signals data transfer jobs (like scancel).

To identify the mount points of the different filesystems on the data transfer machine, use dtinfo. It shows an output like this:

ZIH system	Local directory	Directory on data transfer machine
Taurus	/scratch/ws	/scratch/ws
	/ssd/ws	/ssd/ws
	/beegfs/global0/ws	/beegfs/global0/ws
	/warm_archive/ws	/warm_archive/ws
	/home	/home
	/projects	/projects
Archive		/archiv
Group storage		/grp/<group storage>

Usage of Datamover

Copying data from /beegfs/global0 to /projects filesystem.

marie@login$ dtcp -r /beegfs/global0/ws/marie-workdata/results /projects/p_number_crunch/.

Moving data from /beegfs/global0 to /warm_archive filesystem.

marie@login$ dtmv /beegfs/global0/ws/marie-workdata/results /warm_archive/ws/marie-archive/.

Archive data from /beegfs/global0 to /archiv filesystem.

marie@login$ dttar -czf /archiv/p_number_crunch/results.tgz /beegfs/global0/ws/marie-workdata/results

Warning

Do not generate files in the /archiv filesystem much larger that 500 GB!

Note

The warm archive and the projects filesystem are not writable from within batch jobs. However, you can store the data in the warm_archive using the Datamover.

Transferring Files Between ZIH Systems and Group Drive

1. Copy your private SSH key from ZIH system to login1.zih.tu-dresden.de.

marie@login$ ssh-copy-id -i ~/.ssh/id_rsa.pub login1.zih.tu-dresden.de

1. Now you can access your group drive with the Datamover commands.

Export the name of your group drive.

marie@login$ export GROUP_DRIVE_NAME=???

Note

Please replace ??? with the name of your group drive.

Copying data from your group drive to /beegfs/global0 filesystem.

marie@login$ dtrsync -av dgw.zih.tu-dresden.de:/glw/${GROUP_DRIVE_NAME}/inputfile /beegfs/global0/ws/marie-workdata/.

Copying data from /beegfs/global0 filesystem to your group drive.

marie@login$ dtrsync -av /beegfs/global0/ws/marie-workdata/resultfile dgw.zih.tu-dresden.de:/glw/${GROUP_DRIVE_NAME}/.