Overview

SeaWulf supports secure file transfers using SSH-based tools: rsync, scp, and sftp. Your transfers require two-factor authentication via DUO. To minimize multiple DUO prompts, connect through Stony Brook VPN first.

For more in depth advice, see SeaWulf’s transferring files FAQ: How do I transfer files to and from SeaWulf?

Using scp

scp is simple and good for one-off transfers. Without VPN you may get DUO prompts for each command, so try to bundle files:

scp file1.txt file2.txt your_netid@login.seawulf.stonybrook.edu:/gpfs/home/your_netid/
scp your_netid@login.seawulf.stonybrook.edu:/gpfs/home/your_netid/output.txt ./
    

Or use wildcards or brace expansion to reduce prompts:

scp *.txt your_netid@login.seawulf.stonybrook.edu:subdir
scp your_netid@login.seawulf.stonybrook.edu:'/path/{a,b,c}.txt' ./
    

That groups files into a single DUO authentication effort. 

Using rsync

rsync handles resuming transfers, synchronizing changes, and is more efficient when many files are involved:

rsync -av myfolder/ your_netid@login.seawulf.stonybrook.edu:/gpfs/home/your_netid/myfolder/
rsync -av your_netid@login.seawulf.stonybrook.edu:/gpfs/projects/SmithGroup/data ./data
    

This transfers only differences and supports compression—especially useful for incremental syncs.

Using sftp

sftp opens an interactive session so you can browse and transfer files more flexibly:

sftp your_netid@login.seawulf.stonybrook.edu
sftp> cd /gpfs/home/your_netid
sftp> get myfile.txt
sftp> put localfile.txt
sftp> ls
sftp> bye
    

It prevents repeated DUO prompts if you stay within one session. 

Graphical Options for Windows

SeaWulf also works with graphical tools, but be careful about DUO prompts:

• MobaXTerm: Use "New SFTP session" instead of the sidebar sidebar during SSH, especially if not on VPN. 
• WinSCP: Use default transfer settings and stay connected over VPN to avoid extra DUO challenges.