Getting data on and off.
SCP
Copies files over SSH. Simple and available everywhere. Good for one-off transfers.
RSYNC
Transfers only what has changed, resumes interrupted transfers, and can preserve permissions and ownership.
Better for anything repeated or large. The standard tool for syncing directories between servers.
SFTP
File transfer over SSH, usable with a graphical client such as FileZilla or WinSCP. Convenient for browsing and occasional edits.
Use SFTP rather than plain FTP. FTP sends credentials unencrypted.
WHAT TO WATCH
Preserve ownership and permissions when copying application files, or the application may fail afterwards Compress large transfers For database data, dump to a file and transfer that rather than copying live database files
BETWEEN TWO SERVERS
rsync directly between them is faster than downloading and re-uploading, provided one can reach the other.
AUTOMATING
rsync in a cron job is a common backup approach.
