Secure File Transfers

Secure file transfers are an essential aspect of remote administration. SSH offers two main options for securely transferring files: scp and sftp. Additionally, alternatives such as rsync and rclone provide more advanced functionality for specialized use cases.

Transferring Files via SSH (scp, sftp)

Using scp

scp (secure copy) is a command-line utility that uses SSH to securely transfer files between local and remote systems.

Example:

scp file.txt user@remote-host:/path/to/destination/

This command copies file.txt from the local machine to the specified path on the remote host. To copy files from the remote machine to the local machine:

scp user@remote-host:/path/to/file.txt /local/destination/

scp is often chosen for quick, simple transfers, though it is less efficient than other tools when copying large data sets or synchronizing directories.

Using sftp

sftp (SSH File Transfer Protocol) provides an interactive interface for securely transferring files over SSH. It allows navigation of the remote filesystem and the transfer of files in an interactive manner.

Example:

sftp user@remote-host

Within the sftp session:

• put file.txt uploads a file to the remote system.
• get file.txt downloads a file from the remote system.
• ls lists files in the remote directory.

sftp offers more control over file transfers and is ideal for managing files interactively.

Alternatives to scp: rsync and rclone

While scp and sftp are widely used, tools like rsync and rclone offer advanced features for specific scenarios.

Using rsync with SSH

rsync enables efficient file transfers over SSH, synchronizing files and directories between systems while transferring only the changes. This makes it ideal for backups and large directory synchronizations.

Example (with SSH):

rsync -avz -e ssh file.txt user@remote-host:/path/to/destination/

• -e ssh: Specifies SSH as the transfer method.
• -avz: Enables archive mode (preserving permissions), verbosity, and compression.

This command securely transfers file.txt to the remote system, with rsync ensuring that only changes are transmitted.

Using rclone with SSH

rclone supports file transfers over SSH using the sftp protocol, along with its extensive support for cloud storage providers. It is well-suited for managing files across multiple environments, including cloud storage and remote systems.

Example (with SSH):

rclone copy file.txt :sftp:user@remote-host:/path/to/destination/

In this example, :sftp: ensures that the sftp protocol is used over SSH for secure transfers.

This page outlines secure file transfer methods using SSH and presents alternatives that offer more advanced features. For complex transfers or regular backups, tools like rsync and rclone provide greater flexibility and efficiency.