File Transfer

Home Directories supports several methods for file transfer. Use the links below to learn more about these methods.

SCP

SCP (Secure CoPy) is a simple way of transferring files between two machines that use the SSH protocol. SCP is available as a protocol choice in some graphical file transfer programs and also as a command line program on most Linux, Unix, and Mac OS X systems. SCP can copy single files, but will also recursively copy directory contents if given a directory name.

After Aug 17, 2020, the community clusters will not support password-based authentication for login. Methods that can be used include two-factor authentication (Purdue Login) or SSH keys. If you do not have SSH keys installed, you would need to type your Purdue Login response into the SFTP's "Password" prompt.

Link to section 'Command-line usage:' of 'SCP' Command-line usage:

You can transfer files both to and from Home Directories while initiating an SCP session on either some other computer or on Home Directories (in other words, directionality of connection and directionality of data flow are independent from each other). The scp command appears somewhat similar to the familiar cp command, with an extra user@host:file syntax to denote files and directories on a remote host. Either Home Directories or another computer can be a remote.

Example: Initiating SCP session on some other computer (i.e. you are on some other computer, connecting to Home Directories):

      (transfer TO Home Directories)
      (Individual files) 
$ scp  sourcefile  myusername@data.rcac.purdue.edu:somedir/destinationfile
$ scp  sourcefile  myusername@data.rcac.purdue.edu:somedir/
      (Recursive directory copy)
$ scp -pr sourcedirectory/  myusername@data.rcac.purdue.edu:somedir/

      (transfer FROM Home Directories)
      (Individual files)
$ scp  myusername@data.rcac.purdue.edu:somedir/sourcefile  destinationfile
$ scp  myusername@data.rcac.purdue.edu:somedir/sourcefile  somedir/
      (Recursive directory copy)
$ scp -pr myusername@data.rcac.purdue.edu:sourcedirectory  somedir/

The -p flag is optional. When used, it will cause the transfer to preserve file attributes and permissions. The -r flag is required for recursive transfers of entire directories.

Example: Initiating SCP session on Home Directories (i.e. you are on Home Directories, connecting to some other computer):

      (transfer TO Home Directories)
      (Individual files) 
$ scp  myusername@$another.computer.example.com:sourcefile  somedir/destinationfile
$ scp  myusername@$another.computer.example.com:sourcefile  somedir/
      (Recursive directory copy)
$ scp -pr myusername@$another.computer.example.com:sourcedirectory/  somedir/

      (transfer FROM Home Directories)
      (Individual files)
$ scp  somedir/sourcefile  myusername@$another.computer.example.com:destinationfile
$ scp  somedir/sourcefile  myusername@$another.computer.example.com:somedir/
      (Recursive directory copy)
$ scp -pr sourcedirectory  myusername@$another.computer.example.com:somedir/

The -p flag is optional. When used, it will cause the transfer to preserve file attributes and permissions. The -r flag is required for recursive transfers of entire directories.

Link to section 'Software (SCP clients)' of 'SCP' Software (SCP clients)

Linux and other Unix-like systems:

The scp command-line program should already be installed.

Microsoft Windows:

MobaXterm
Free, full-featured, graphical Windows SSH, SCP, and SFTP client.
Command-line scp program can be installed as part of Windows Subsystem for Linux (WSL), or Git-Bash.

Mac OS X:

The scp command-line program should already be installed. You may start a local terminal window from "Applications->Utilities".
Cyberduck is a full-featured and free graphical SFTP and SCP client.

Globus

Link to section 'Globus' of 'Globus' Globus

Globus, previously known as Globus Online, is a powerful and easy to use file transfer service for transferring files virtually anywhere. It works within RCAC's various research storage systems; it connects between RCAC and remote research sites running Globus; and it connects research systems to personal systems. You may use Globus to connect to your home, scratch, and Fortress storage directories. Since Globus is web-based, it works on any operating system that is connected to the internet. The Globus Personal client is available on Windows, Linux, and Mac OS X. It is primarily used as a graphical means of transfer but it can also be used over the command line.

Link to section 'Link to section 'Globus Web:' of 'Globus' Globus Web:' of 'Globus' Link to section 'Globus Web:' of 'Globus' Globus Web:

Navigate to http://transfer.rcac.purdue.edu
Click "Proceed" to log in with your Purdue Career Account.
On your first login it will ask to make a connection to a Globus account. Accept the conditions.
Now you are at the main screen. Click "File Transfer" which will bring you to a two-panel interface (if you only see one panel, you can use selector in the top-right corner to switch the view).
You will need to select one collection and file path on one side as the source, and the second collection on the other as the destination. This can be one of several Purdue endpoints, or another University, or even your personal computer (see Personal Client section below).

The RCAC collections are as follows. A search for "Purdue" will give you several suggested results you can choose from, or you can give a more specific search.

Home Directory storage: "Purdue Research Computing - Home Directories", however, you can start typing "Purdue" and "Home Directories" and it will suggest appropriate matches.
Weber scratch storage: "Purdue Weber Cluster", however, you can start typing "Purdue" and "Weber and it will suggest appropriate matches. From here you will need to navigate into the first letter of your username, and then into your username.
Research Data Depot: "Purdue Research Computing - Data Depot", a search for "Depot" should provide appropriate matches to choose from.
Fortress: "Purdue Fortress HPSS Archive", a search for "Fortress" should provide appropriate matches to choose from.

From here, select a file or folder in either side of the two-pane window, and then use the arrows in the top-middle of the interface to instruct Globus to move files from one side to the other. You can transfer files in either direction. You will receive an email once the transfer is completed.

Link to section 'Link to section 'Globus Personal Client setup:' of 'Globus' Globus Personal Client setup:' of 'Globus' Link to section 'Globus Personal Client setup:' of 'Globus' Globus Personal Client setup:

Globus Connect Personal is a small software tool you can install to make your own computer a Globus endpoint on its own. It is useful if you need to transfer files via Globus to and from your computer directly.

On the "Collections" page from earlier, click "Get Globus Connect Personal" or download a version for your operating system it from here: Globus Connect Personal
Name this particular personal system and follow the setup prompts to create your Globus Connect Personal endpoint.
Your personal system is now available as a collection within the Globus transfer interface.

Link to section 'Link to section 'Globus Command Line:' of 'Globus' Globus Command Line:' of 'Globus' Link to section 'Globus Command Line:' of 'Globus' Globus Command Line:

Globus supports command line interface, allowing advanced automation of your transfers.

To use the recommended standalone Globus CLI application (the globus command):

First time use: issue the globus login command and follow instructions for initial login.
Commands for interfacing with the CLI can be found via Using the Command Line Interface, as well as the Globus CLI Examples pages.

Link to section 'Link to section 'Sharing Data with Outside Collaborators' of 'Globus' Sharing Data with Outside Collaborators' of 'Globus' Link to section 'Sharing Data with Outside Collaborators' of 'Globus' Sharing Data with Outside Collaborators

Globus allows convenient sharing of data with outside collaborators. Data can be shared with collaborators' personal computers or directly with many other computing resources at other institutions. See the Globus documentation on how to share data:

https://docs.globus.org/how-to/share-files/

For links to more information, please see Globus Support page and RCAC Globus presentation.

FTP / SFTP

FTP is not supported on any research systems because it does not allow for secure transmission of data. Use SFTP instead, as described below.

SFTP (Secure File Transfer Protocol) is a reliable way of transferring files between two machines. SFTP is available as a protocol choice in some graphical file transfer programs and also as a command-line program on most Linux, Unix, and Mac OS X systems. SFTP has more features than SCP and allows for other operations on remote files, remote directory listing, and resuming interrupted transfers. Command-line SFTP cannot recursively copy directory contents; to do so, try using SCP or graphical SFTP client.

Link to section 'Command-line usage' of 'FTP / SFTP' Command-line usage

You can transfer files both to and from Home Directories while initiating an SFTP session on either some other computer or on Home Directories (in other words, directionality of connection and directionality of data flow are independent from each other). Once the connection is established, you use put or get subcommands between "local" and "remote" computers. Either Home Directories or another computer can be a remote.

Example: Initiating SFTP session on some other computer (i.e. you are on another computer, connecting to Home Directories):

$ sftp myusername@data.rcac.purdue.edu

      (transfer TO Home Directories)
sftp> put sourcefile somedir/destinationfile
sftp> put -P sourcefile somedir/

      (transfer FROM Home Directories)
sftp> get sourcefile somedir/destinationfile
sftp> get -P sourcefile somedir/

sftp> exit

The -P flag is optional. When used, it will cause the transfer to preserve file attributes and permissions.

Example: Initiating SFTP session on Home Directories (i.e. you are on Home Directories, connecting to some other computer):

$ sftp myusername@$another.computer.example.com

      (transfer TO Home Directories)
sftp> get sourcefile somedir/destinationfile
sftp> get -P sourcefile somedir/

      (transfer FROM Home Directories)
sftp> put sourcefile somedir/destinationfile
sftp> put -P sourcefile somedir/

sftp> exit