LSDF Online Storage: Secure Shell
Secure Shell or SSH refers to both a cryptographic network protocol as well a number of applications that can be used to establish a secure connect with a service provider like the LSDF Online Storage. SSH is typically used to login interactively to a remote machine and execute commands, but it can also be used to transfer file using the protocols SSH File Transfer Protocol (SFTP) or Secure Copy (SCP). The SSH Filesystem (SSHFS) is a file system client based on the SSH protocol which allows to locally mount and interact with directories and files located on a remote server.
SSH access to the LSDF Online Storage is provided via a cluster of login servers reachable at the address os-login.lsdf.kit.edu.
Using SSH on Linux or Mac OS
To interactively login to the LSDF Online Storage login cluster enter the following command in a linux shell or Mac OS terminal
$ ssh <USERNAME>@os-login.lsdf.kit.edu
where <USERNAME> needs to be replaced with your actual user name, e.g. xy1234. The command above will ask for a password to grant access to the login server.
To avoid being asked for a password on every login, password-less access can be configured by distributing a public key to the login server. To create a new set of keys issue the following command:
$ ssh-keygen
The newly generated key should be password protected.
To copy the public part of your key pair to the login server issue the following command:
$ ssh-copy-id -i ~/.ssh/id_rsa.pub <USERNAME>@os-login.lsdf.kit.edu
Subsequent logins will use the key instead of a password to authenticate to the login server.
Attention: Posix style file commands (for instance chmod) must not be applied on files on a CIFS share. This may revoke sharing and Access Lists (ACLs), steering the access to the files.
Using SCP on Linux or Mac OS
SCP is a protocol that allows secure data transfer between a local and a remote computer or between two remote computers. To transfer the data to or from the LSDF Online Storage, you can execute the following commands:
$ scp <LOCAL PATH>/<FILES(S)> <USERNAME>@os-login.lsdf.kit.edu:<REMOTE PATH>/ $ scp <USERNAME>@os-login.lsdf.kit.edu:<REMOTE PATH> <LOCAL PATH>/<FILES(S)>
Please be aware that symbolic links will usually not be copied as links.
Using SFTP on Linux or Mac OS
The following example illustrates the usage of SFTP in a linux shell:
$ sftp xy1234@os-login.lsdf.kit.edu Connecting to os-login.lsdf.kit.edu<br> xy1234@os-login.lsdf.kit.edu's password: sftp> ls snapshots temp test sftp> help ... sftp> put myfile sftp> get myfile
Further details on the usage of the SFTP command line client can be found on the man page.
Using SSHFS on Linux or Mac OS
SSHFS is a file system implementation allowing users to mount and interact with directories and files located on a remote server over a normal ssh connection. Using SSHFS a mounted remote file system behaves similar to other local volumes or files systems. In situations where higher performance and / or simultaneous access to the LSDF Online Storage by many users are required other protocols like NFS, CIFS or WebDAV might be better suited.
Installation
SSHFS is available on many linux distribution via the standard software distribution channels.
On Debian/Ubuntu like systems:
$ apt-get install sshfs
On RedHat/CentOS like systems:
$ yum install fuse-sshfs
Mounting a Remote File System Interactively (as normal user)
To mount a remote file system via command line:
$ mkdir mountpoint $ sshfs <USERNAME>@os-login.lsdf.kit.edu:/lsdf/kit/inst/projects ./mointpoint
Mounting a Remote File System with /etc/fstab (as root)
Add (as root) a line to your /etc/fstab describing how to mount the remote folder:
sshfs <USERNAME>@os-login.lsdf.kit.edu:/lsdf/kit/<INSTITUTE>/projects <MOUNTPOINT> fuse uid=<UID>,gid=<GID>,umask=0,allow_other,defaults,auto 0 0
where <UID is the numerical user id of the user the remote mount will be mapped to, <GID> is the numerical group id of the user the remote mount will be mapped to, <USERNAME> is the user name user for the SSH login, <MOUNTPOINT> is the local mount point (directory).
For example:
sshfs xy1234@os-login.lsdf.kit.edu:/lsdf/kit/scc/projects /mnt/mountpoint fuse uid=7777,gid=12345,umask=0,allow_other,defaults,auto 0 0
In order to make the above example work, password-less ssh login with keys needs to be properly configured. Mount the remote file system by issuing the following command (as root):
$ mount /mnt/mountpoint
Using Secure Shell with Windows
Please find below a list of Secure Shell clients for Windows and MacOS (without any claim to completeness):
| MobaXterm | https://mobaxterm.mobatek.net/ |
| PuTTY | https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html |
| WinSCP | http://winscp.net/eng/download.php |
| FileZilla | http://sourceforge.net/projects/filezilla/ |
| WebDrive | https://southrivertech.com/products/webdrive/download/ |
| Cygwin | http://cygwin.com/install.html |
| Windows 10 subsystem for Linux | https://msdn.microsoft.com/de-de/commandline/wsl/install_guide |
The following software packages provide network drive functionality based on SFTP:
| WebDrive (for Windows, Mac, iOS, Android) | http://www.southrivertechnologies.com/download/downloadwd.html |
| SFTPNetDrive (for Windows) | http://www.sftpnetdrive.com/ |
| NetDrive (for Windows) | http://www.netdrive.net/ |
| ExpanDrive (for Windows and Mac) | http://www.expandrive.com/expandrive |
| MountainDuck (for Windows and Mac) | https://mountainduck.io/ |
