SSH-based Data Transfer

Last update: March 17, 2026

TACC User Support recommends using SSH based tools for file transfers less than 200GB. For large file transfers (e.g.: > 200 GB), Globus is recommended. See the TACC Globus Guide.

You can access SSH utilities via a client application, a GUI interface, or on the command-line via a Terminal application.

1. SSH Command-line (CLI) tools e.g. scp, sftp, rsync
2. Graphical User Interface (GUI) tools, e.g. Cyberduck.

There are many SSH-compatible clients across all platforms, and almost any modern SSH client will successfully interoperate with TACC systems. While we provide examples using the Cyberduck application, we encourage you to choose whichever transfer client is most familiar and most functional on your platform. Many SSH clients are organized to assist with specific workflows.

For SSH-based transfers, you will need two pieces of information in addition to your TACC username/password combination: the HOSTNAME of the system you are transferring to, and the PATH that you are attempting to access. Especially if you are uploading data, it is very important that you select the correct path for the resource and project - otherwise your data will be at risk of being lost or misplaced. The path may include a functional name such as /scratch/ or a resource name such as /corral/.

Transfer files between TACC HPC resources and other Linux-based systems using either scp, sftp, or rsync. All three utilities are available in the Mac Terminal app. Windows SSH clients typically include scp-based file transfer capabilities.

To simplify the data transfer process, we recommend that Windows users follow the How to Transfer Data with Cyberduck guide as detailed below.

SSH Command-Line Examples

Determining Paths

Before beginning data transfer with command-line tools, you will need to know:

• the path to your data file(s) on your local system
• the path to your transfer directory on the remote system

In order to transfer your project data, you will first need to know where the files are located on your local system.

To do so, navigate to the location of the files on your computer. This can be accomplished on a Mac by using the Finder application or on Windows with File Explorer application. Common locations for user data at the user's home directory, the Desktop and My Documents.

Once you have identified the location of the files, you can right-click on them and select either Get Info (on Mac) or Properties (on Windows) to view the path location on your local system.

Figure 1. Use Get Info to determine "Where" the path of your data file(s) is

For example, a file located in a folder named portal-data under Documents would have the following path:

On Mac	/Users/username/Documents/portal-data/my_file.txt
On Windows	\Users\username\My Documents\portal-data\my_file.txt

Using scp

The Linux scp (secure copy) utility is a component of the OpenSSH suite. Assuming your Lonestar6 username is bjones, a simple scp transfer that copies a file named myfile from your local Linux system to Lonestar6 $HOME would look like this: (note the colon at end of line)

localhost$ scp ./myfile bjones@ls6.tacc.utexas.edu:  

You can use wildcards, but you need to be careful about when and where you want wildcard expansion to occur. For example, to push all files ending in .txt from the current directory on your local machine to /work/01234/bjones/scripts on Lonestar6:

localhost$ scp *.txt bjones@ls6.tacc.utexas.edu:/work/01234/bjones/ls6

To delay wildcard expansion until reaching Lonestar6, use a backslash (\) as an escape character before the wildcard. For example, to pull all files ending in .txt from /work/01234/bjones/scripts on Lonestar6 to the current directory on your local system:

localhost$ scp bjones@ls6.tacc.utexas.edu:/work/01234/bjones/ls6/\*.txt .

You can of course use shell or environment variables in your calls to scp. For example:

localhost$ destdir="/work/01234/bjones/ls6/data"
localhost$ scp ./myfile bjones@ls6.tacc.utexas.edu:$destdir

You can also issue scp commands on your local client that use Lonestar6 environment variables like $HOME, $WORK, and $SCRATCH. To do so, use a backslash (\) as an escape character before the $; this ensures that expansion occurs after establishing the connection to Lonestar6:

localhost$ scp ./myfile bjones@ls6.tacc.utexas.edu:\$SCRATCH/data   # Note backslash

Avoid using scp for recursive transfers of directories that contain nested directories of many small files:

localhost$ scp -r ./mydata     bjones@ls6.tacc.utexas.edu:\$SCRATCH  # DON'T DO THIS

Instead, use tar to create an archive of the directory, then transfer the directory as a single file:

localhost$ tar cvf ./mydata.tar mydata                             # create archive
localhost$ scp     ./mydata.tar bjones@ls6.tacc.utexas.edu:\$WORK  # transfer archive

Consult the scp man pages for more information:

login1$ man scp

Using rsync

The rsync (remote synchronization) utility is another way to keep your data up to date. In contrast to scp, rsync transfers only the actual changed parts of a file (instead of transferring an entire file). Hence, this selective method of data transfer can be much more efficient than scp. The following example demonstrates usage of the rsync command for transferring a file named myfile.c from its current location on Stampede to Frontera's $DATA directory.

localhost$ rsync       mybigfile bjones@frontera.tacc.utexas.edu:\$WORK/data
localhost$ rsync -avtr mybigdir  bjones@frontera.tacc.utexas.edu:\$WORK/data

The options on the second transfer are typical and appropriate when synching a directory:

• this is a recursive update (-r)
• with verbose (-v) feedback;
• the synchronization preserves time stamps (-t) as well as symbolic links
• and other meta-data (-a).

Because rsync only transfers changes, recursive updates with rsync may be less demanding than an equivalent recursive transfer with scp.

login1$ rsync myfile.c TACC-username@frontera.tacc.utexas.edu:/data/01698/TACC-username/data

An entire directory can be transferred from source to destination by using rsync as well. For directory transfers the options -avtr will transfer the files recursively (-r option) along with the modification times (-t option) and in the archive mode (-a option) to preserve symbolic links, devices, attributes, permissions, ownerships, etc. The -v option (verbose) increases the amount of information displayed during any transfer. The following example demonstrates the usage of the -avtr options for transferring a directory named gauss from the present working directory on Stampede to a directory named data in the $WORK file system on Frontera.

login1$ rsync -avtr ./gauss \
TACC-username@frontera.tacc.utexas.edu:/data/01698/TACC-username/data

For more rsync options and command details, run the command rsync -h or:

login1$ man rsync

Using sftp

sftp is a file transfer program that allows you to interactively navigate between your local file system and the remote secure system. To transfer a file (ex. my_file.txt) to the remote secure system via sftp, open a terminal on your local computer and navigate to the path where your data file is located.

On Mac	localhost$ cd ~/Documents/portal-data/
On Windows	localhost$ cd %HOMEPATH%\Documents\portal-data\

For example, assume your TACC username is bjones and you have an allocation on Stampede3. An sftp transfer that pushes my_file.txt from the current directory of your local computer to your home directory on TACC's Stampede3 system would look like this:

localhost$ sftp bjones@stampede3.tacc.utexas.edu:/transfer/directory/path
Password:
TACC Token Code:
Connected to host.
Changing to:
  /transfer/directory/path
sftp>

Once you've logged into the remote secure system and have been redirected to your transfer directory, confirm your location on the server:

sftp> pwd
Remote working directory:
/transfer/directory/path

To list the files currently in your transfer directory:

sftp> ls
utaustin_dir.txt

To list the files currently in your local directory:

sftp> lls
my_file.txt

To transfer my_file.txt from your local computer to your transfer directory:

sftp> put my_file.txt
Uploading my_file.txt to /transfer/directory/path
my_file.txt     100% ##  #.#          KB/s   ##:#

To double-check if the transfer succeeded:

sftp> ls
my_file.txt
utaustin_dir.txt

To exit out of sftp:

sftp> bye
localhost1$

More Reading

• Linux Foundation's classic article "How to Securely Transfer Files Between Servers with scp".
• Linux.com's excellent article "Get to Know rsync"

Example: Cyberduck GUI

TACC staff recommends the open-source Cyberduck utility for both Windows and Mac users that do not already have a preferred tool. Cyberduck is a free graphical user interface for data transfer and is an alternative to using the command line. With a drag-and-drop interface, it is easy to transfer a file from your local system (your laptop) to the remote secure system (TACC resource). You can use Cyberduck for Windows or macOS.

Download Cyberduck

Click on the "Open Connection" button in the top right corner of the Cyberduck window to open a connection configuration window (as shown below), select the transfer mechanism, and type in the server name "stampede3.tacc.utexas.edu". Add your username and password in the spaces provided, and if the "more options" area is not shown click the small triangle or button to expand the window; this will allow you to enter the path to your project area so that when Cyberduck opens the connection you will immediately see your data. Then click the "Connect" button to open your connection.

Once installed, click "Open Connection" in the top left corner of your Cyberduck window.

To set up a connection, type in the server name, host. Add your TACC username and password in the spaces provided. If the "More Options" area is not shown, click the small triangle button to expand the window; this will allow you to enter the path to your transfer directory, /transfer/directory/path, so that when Cyberduck opens the connection you will immediately be in your individualized transfer directory on the system. Click the "Connect" button to open your connection.

Once connected, you can navigate through your remote file hierarchy using familiar graphical navigation techniques. You may also drag-and-drop files into and out of the Cyberduck window to transfer files to and from Frontera.

Consult Figure 3. below to ensure the information you have provided is correct. If you have not done so already, replace the "Path" with the path to your individualized transfer directory.

Once connected, you can navigate through your remote file hierarchy using the graphical user interface. You may also drag-and-drop files from your local computer into the Cyberduck window to transfer files to the system.