Data Transfer – PERUN Supercomputer¶

1. Introduction¶

You can transfer files to and from the PERUN supercomputer using:

Terminal-based tools: scp, rsync, sftp
Graphical applications: MobaXterm, WinSCP (Windows)

All commands must be executed from your local computer, not from PERUN.

2. Using scp (Secure Copy)¶

scp allows you to securely copy files between your computer and PERUN.

2.1 Basic Syntax¶

Example – scp Syntax

scp [options] <source> <destination>

2.2 Transfer from Local → PERUN¶

Example – Upload a File to PERUN

scp localfile.txt <username>@login01.perun.tuke.sk:/home/<username>/
scp localfile.txt <username>@login02.perun.tuke.sk:/home/<username>/

Example – Upload a Folder to PERUN

scp -r myfolder <username>@login01.perun.tuke.sk:/home/<username>/project/
scp -r myfolder <username>@login02.perun.tuke.sk:/home/<username>/project/

2.3 Transfer from PERUN → Local¶

Example – Download a File from PERUN

scp <username>@login01.perun.tuke.sk:/home/<username>/results/output.txt .
scp <username>@login02.perun.tuke.sk:/home/<username>/results/output.txt .

Example – Download a Directory from PERUN

scp -r <username>@login01.perun.tuke.sk:/home/<username>/results ./local_results
scp -r <username>@login02.perun.tuke.sk:/home/<username>/results ./local_results

3. Using rsync for Efficient Transfers¶

rsync is recommended for large or frequently updated data. It transfers only changed parts of files.

3.1 Basic Syntax¶

Example – rsync Syntax

rsync [options] <source> <destination>

3.2 Transfer from Local → PERUN¶

Example – Upload a File with Progress

rsync -avh --progress data.csv <username>@login01.perun.tuke.sk:/home/<username>/data/
rsync -avh --progress data.csv <username>@login02.perun.tuke.sk:/home/<username>/data/

Example – Upload a Directory

rsync -avh myproject/ <username>@login01.perun.tuke.sk:/home/<username>/myproject/
rsync -avh myproject/ <username>@login02.perun.tuke.sk:/home/<username>/myproject/

3.3 Transfer from PERUN → Local¶

Example – Download a File

rsync -avh <username>@login01.perun.tuke.sk:/home/<username>/results/output.txt .
rsync -avh <username>@login02.perun.tuke.sk:/home/<username>/results/output.txt .

Example – Download a Folder

rsync -avh --progress <username>@login01.perun.tuke.sk:/home/<username>/results ./results
rsync -avh --progress <username>@login02.perun.tuke.sk:/home/<username>/results ./results

3.4 Useful rsync Options¶

-a – archive mode (preserves permissions and structure)
-v – verbose output
-h – human-readable formatting
--progress – show progress information
-z – compression during transfer

4. Using sftp (Secure File Transfer Protocol)¶

sftp provides an interactive shell for browsing and transferring files securely.

4.1 Start an Interactive Session¶

Example – Start SFTP

sftp <username>@login01.perun.tuke.sk
sftp <username>@login02.perun.tuke.sk

Example – Open Remote Folder with SFTP

sftp <username>@login01.perun.tuke.sk:/home/<username>/data
sftp <username>@login02.perun.tuke.sk:/home/<username>/data

4.2 Download a File from PERUN¶

Example – Download a File with SFTP

sftp <username>@login01.perun.tuke.sk:/home/<username>/results/output.txt ./local_output.txt
sftp <username>@login02.perun.tuke.sk:/home/<username>/results/output.txt ./local_output.txt

4.3 Batch (Automated) Transfers¶

Example – Automated SFTP Upload

batchfile:

cd /home/<username>/upload
put file*.txt

Run with:

sftp -b batchfile <username>@login01.perun.tuke.sk
sftp -b batchfile <username>@login02.perun.tuke.sk

5. Using a Non‑Default SSH Key¶

If your SSH key is stored outside the default ~/.ssh/ directory, specify it manually:

Example – Specify a Custom SSH Key

ssh  -i /path/to/key <username>@login01.perun.tuke.sk
scp  -i /path/to/key localfile.txt <username>@login01.perun.tuke.sk:/home/<username>/
rsync -avh -e "ssh -i /path/to/key" myfolder/ <username>@login01.perun.tuke.sk:/home/<username>/myfolder/
sftp -i /path/to/key <username>@login01.perun.tuke.sk

Keep your private key secure at all times.