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Datamovers are dedicated nodes on each HPC cluster that are designed for transferring data FROM/TO a cluster.

Hostnames and IPs

Marconi:

  • alias: data.marconi.cineca.it
  • hostnames and IPs:
    • dmover1.marconi.cineca.it - 130.186.17.140
    • dmover2.marconi.cineca.it - 130.186.17.141

Marconi100:

  • alias: data.m100.cineca.it
  • hostnames and IPs:
    • dmover1.m100.cineca.it - 130.186.16.214
    • dmover2.m100.cineca.it - 130.186.16.215

Galileo100:

  • alias: data.g100.cineca.it
  • hostnames and IPs:
    • dmover1.g100.cineca.it - 130.186.16.212
    • dmover2.g100.cineca.it - 130.186.16.213

Leonardo:

  • alias: data.leonardo.cineca.it
  • hostnames and IPs:
    • dmover1.leonardo.cineca.it - 131.175.44.50
    • dmover2.leonardo.cineca.it - 131.175.44.51
    • dmover3.leonardo.cineca.it - 131.175.44.53

Main features

This transfer service is containerized, and there are many differences between these nodes and the login nodes.

First of all, on datamovers, there is no CPU time limit, that allows long data transfers. Unlike, on login nodes, there is a 10-minute of CPU time limit that usually interrupts the transfer of a large amount of data.
The only available commands are scp, rsync, sftp, wget, and curl. For security reasons, the shell is not available, and it is not possible to open interactive sessions.
Like the login nodes, the authentication is based on SSH protocol. There are only 2 possible authentication methods:

  1.  publickey: it only accepts valid SSH certificates, obtained via 2-Factor Authentication. No private/public keys generated in other ways are accepted.
  2.  hostbased: if you are already logged into a CINECA HPC cluster and try to use a datamover from a login node, the SSH daemon on the datamover recognizes you are already authenticated on a CINECA HPC cluster and that is enough.

Remark: The host-based authentication does not work inside a job batch. If you want to use a datamover inside a job batch you have to copy a valid SSH certificate inside your ~/.ssh directory.

Finally, when you authenticate yourself on a datamover, you will land on a fake home directory, /home, which is not your true $HOME directory. You can check using sftp, e.g. "sftp <username>@data.leonardo.cineca.it: "
This behavior has 2 side effects:

  1. if you want to transfer files FROM/TO your $HOME directory you have to specify the absolute path, the same is true for your $WORK, $CINECA_SCRATCH filesystems
  2. You cannot use the SSH configuration stored in your remote ~/.ssh/ directory (~/.ssh/config).

Listing Directory via sftp

If you need to list files on a cluster where login nodes are offline, you can rely on datamover service via the sftp command:

  $  sftp <username>@data.<cluster_name>.cineca.it:/path/to/be/listed/
  Connected to data.<cluster_name>.cineca.it
  Changing to: /path/to/be/listed/
  sftp>

One entered the sftp session, the familiar pwd, cd /path/to/, ls commads are available to explore the remote filesystem, together with the sftp command lpwd, lcd /path/to/, lls. You can also transfer data from the sftp session, see the appropriate section below.

At present M100 login nodes are offline, so you need to resort to the sftp command to explore M100 filesystem. For instance:

  $ sftp fcola000@data.m100.cineca.it:/m100_scratch/userinternal/fcola000/ 
  Connected to data.m100.cineca.it. 
  Changing to: /m100_scratch/userinternal/fcola000/ 
  sftp> cd cuda
  sftp> ls -l
  drwxr-xr-x    3 fcola000 interactive     4096 Feb 11  2021 targets
  sftp> pwd
  Remote working directory: /m100_scratch/userinternal/fcola000/cuda
  sftp>

Available transfer tools

rsync

There are 2 possible ways to use rsync via datamovers:

  1. You need to upload or download data FROM/TO your local machine TO/FROM a CINECA HPC cluster
    $ rsync -PravzHS /absolute/path/from/file <username>@data.<cluster_name>.cineca.it:/absolute/path/to/
    $ rsync -PravzHS  <username>@data.<cluster_name>.cineca.it:/absolute/path/from/file /absolute/path/to/
  2. You need to transfer files between 2 CINECA HPC clusters
    $ ssh -xt <username>@data.<cluster_name_1>.cineca.it rsync -PravzHS /absolute/path/from/file <username>@data.<cluster_name_2>.cineca.it:/absolute/path/to/
    $ ssh -xt <username>@data.<cluster_name_1>.cineca.it rsync -PravzHS <username>@data.<cluster_name_2>.cineca.it:/absolute/path/from/file  /absolute/path/to/

scp

There are 3 possible ways to use scp via datamovers:

  1. You need to upload or download data FROM/TO your local machine TO/FROM a CINECA HPC cluster
    $ scp /absolute/path/from/file <username>@data.<cluster_name>.cineca.it:/absolute/path/to/
    $ scp  <username>@data.<cluster_name>.cineca.it:/absolute/path/from/file /absolute/path/to/


  2. You need to transfer files between 2 CINECA HPC clusters
    $ ssh -xt <username>@data.<cluster_name_1>.cineca.it scp /absolute/path/from/file <username>@data.<cluster_name_2>.cineca.it:/absolute/path/to/
    $ ssh -xt <username>@data.<cluster_name_1>.cineca.it scp <username>@data.<cluster_name_2>.cineca.it:/absolute/path/from/file  /absolute/path/to/
  3. You need to transfer files between 2 CINECA HPC clusters using your local machine as a bridge. We strongly suggest not using this option because it has very low transfer performance, each file you move from one cluster to another will pass through your local machine
    $ scp -3  <username>@data.<clusterr_name_1>.cineca.it:/absolute/path/from/file  data.<cluster_name_2>.cineca.it:/absolute/path/from/file

sftp

There are 2 possible ways to use scp via datamovers:

  1. You need to upload or download data FROM/TO your local machine TO/FROM a CINECA HPC cluster
    $ sftp <username>@data.<cluster_name>.cineca.it:/absolute/remote/path/to/
    sftp> put relative/local/path/to/file
    Uploading /absolute/local/path/to/file to     /absolute/remote/path/to/file
    file                                                                                                 100%  414   365.7KB/s   00:00     
    sftp> get relative/remote/path/to/file 
    Fetching /absolute/remote/path/to/file to file 
    file                                                                                                     100% 1455KB  19.0MB/s   00:00    
    sftp> 
  2. You need to transfer files between 2 CINECA HPC clusters
    $ ssh -xt <username>data.<cluster_name_1>.cineca.it sftp <username>@data.<cluster_name_2>.cineca.it:/absolute/path/to/

It is also possible to use the flag -b and execute sftp in batch mode.

wget

Sometimes, the 10-minute CPU time limit or the 4-hour wall time limit on the serial queue is not enough to download a large dataset for ML. In this case, you can use wget from the datamover. Here you can find a simple example

    $ ssh -xt <username>@data.<cluster_name>.cineca.it wget http://ftp.gnu.org/gnu/wget/wget2-2.0.0.tar.gz -P /absolute/path/to/

Please note that is mandatory to use the flag -P with the absolute path of the destination folder, because of the fake /home directory.

curl

Sometimes, the 10-minute CPU time limit or the 4-hour wall time limit on the serial queue is not enough to download a large dataset for ML. In this case, you can use curl from the datamover. Here you can find a simple example

    $ ssh -xt <username>@data.<cluster_name>.cineca.it curl https://curl.se/download/curl-8.2.1.tar.gz --output /absolute/path/to/curl-8.2.1.tar.gz

Please note that is mandatory to use the flag --output with the absolute path of the destination file, because of the fake /home directory.

GridFTP

Datamover nodes of each CINECA HPC cluster host the GridFTP servers. On the datamover we have enabled the authentication via ssh as an alternative to the x509 certificate. Of course, you have to keep in mind that the SSH authentication is based on the ssh certificate, obtained via 2-Factor authentication.

Transfer data between 2 CINECA HPC clusters


    $ globus-url-copy -vb sshftp://<username>@gftp.<cluster_name_1>.cineca.it:22/absolute/path/from/directory  sshftp://<username>@gftp.<cluster_name_2>.cineca.it:22/absolute/path/to/
    $ globus-url-copy -vb gsiftp://<username>@gftp.<cluster_name_1>.cineca.it:2811/absolute/path/from/directory  gsiftp://<username>@gftp.<cluster_name_2>.cineca.it:2811/absolute/path/to/

CAVEAT: at present the gsiftp mode is not available on Leonardo.

Transfer data FROM/TO local machine TO/FROM a CINECA HPC cluster


    $ globus-url-copy -vb /absolute/path/from/directory  sshftp://<username>@gftp.<cluster_name_2>.cineca.it:22/absolute/path/to/
    $ globus-url-copy -vb /absolute/path/from/directory  gsiftp://<username>@gftp.<cluster_name_2>.cineca.it:2811/absolute/path/to/

    $ globus-url-copy -vb sshftp://<username>@gftp.<cluster_name_1>.cineca.it:22/absolute/path/from/directory /absolute/path/to/
    $ globus-url-copy -vb gsiftp://<username>@gftp.<cluster_name_1>.cineca.it:2811/absolute/path/from/directory /absolute/path/to/

Please note that authentication via ssh certificate is not available on Globus online


Additional transfer modes will be explored and reported in the next future.

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