20. Transferring data to/from the system

To transfer data to and from hexagon use the following address:

stallo.uit.no

This address has nodes with 10Gb network interfaces.

Basic tools (scp, sftp)

Standard scp command and sftp clients can be used:

ssh stallo.uit.no
ssh -l <username> stallo.uit.no

sftp stallo.uit.no
sftp <username>@stallo.uit.no

mounting the file system on you local machine using sshfs:

for linux users:
sshfs [user@]stallo.uit.no:[dir] mountpoint [options]
eg.
sshfs steinar@stallo.uit.no:  /home/steinar/stallo-fs/

Windows users may buy and install expandrive.

High-performance tools

Default ssh client and server on stallo login nodes is openssh package with applied HPN patches. By using a hpnssh client on the other end of the data transfer throughput will be increased.

To use this feature you must have a HPN patched openssh version. You can check if your ssh client has HPN patches by issuing:

ssh -V

if the output contains the word "hpn" followed by version and release then you can make use of the high performance features.

Transfer can then be speed up either by disabling data encryption, AFTER you have been authenticated or logged into the remote host (NONE cipher), or by spreading the encryption load over multiple threads (using MT-AES-CTR cipher).

NONE cipher

This cipher has the highest transfer rate. Keep in mind that data after authentication is NOT encrypted, therefore the files can be sniffed and collected unencrypted by an attacker. To use you add the following to the client command line:

-oNoneSwitch=yes -oNoneEnabled=yes

Anytime the None cipher is used a warning will be printed on the screen:

"WARNING: NONE CIPHER ENABLED"

If you do not see this warning then the NONE cipher is not in use.

MT-AES-CTR

If for some reason (eg: high confidentiality) NONE cipher can't be used, the multithreaded AES-CTR cipher can be used, add the following to the client command line (choose one of the numbers):

-oCipher=aes[128|192|256]-ctr

or:

-caes[128|192|256]-ctr.

Subversion and rsync

The tools subversion and rsync is also available for transferring files.