Data Transfer

Transfer Tools

Type	Software	Remarks	Executable on				Transfer from/to
			Local°	bwUniCluster	bwForCluster	www	bwHPC cluster	SDS@hd
Command-line	scp	Throughput < 150 MB/s (depending on cipher)	+	+	+		+
	sftp		+	+	+		+	+
	rsync		+	+	+		+
	rdata	Throughput of 350-400 MB/s		+				+
	wget	Download from http/ftp address only	+	+	+	+
Graphical	WinSCP	based on SCP/SFTP, Windows only	+				+	+
	FileZilla	based on SFTP	+				+	+

° Depending on the installed operating system (OS).

Linux/Unix/Mac commandline sftp/scp Usage Examples

sftp

> sftp  ka_xy1234@bwfilestorage.lsdf.kit.edu
Connecting to bwfilestorage.lsdf.kit.edu<br>
ka_xy1234@bwfilestorage.lsdf.kit.edu's password: 
sftp> ls
snapshots
temp test
sftp> help
...
sftp> put myfile
sftp> get myfile

scp

> scp mylocalfile ul_xy1234@justus.uni-ulm.de: # copies to home directory

Using SFTP from Windows and Mac graphical clients

Windows clients do not have a SCP/SFTP client installed by default, so it needs to be installed before this protocol can be used.

Tools for example:

• OpenSSH
• Putty suite (for Windows and Unix)
• WinSCP (for Windows)
• FileZilla (for Windows, Mac and Linux)
• Cygwin (for Windows)

network drive over SFTP:

• WebDrive (for Windows and Mac)
• SFTP Net Drive (ELDOS) (for Windows)
• NetDrive (for Windows)
• ExpanDrive (for Windows and Mac)

Best practices

Ciphers

Encrypting all the transferred data via scp/sftp takes time, which can become significant for really large data transfers.

In these cases, you can choose a faster encryption cipher to speed up that part of your data transfer via options to ssh/sftp. In our tests, these ciphers have had the listed transfer speedups over the default. If speedups are noticeable for you depends on processor type, network connection and the used hard disk.

Cipher	performance
chacha20-poly1305@openssh.com (default)	100%
aes128-gcm@openssh.com	~200%
aes128-ctr	~188%

With ssh/sshfs you can use different ciphers with the -c option:

ssh -c aes128-gcm@openssh.com

A list of available ciphers should be available with the command

ssh -Q cipher