Remote Access to Linux Computers

Linux computing resources can be accessed from off-campus locations (as well as different locations on-campus).

ssh

ssh can be used for remote command-line access to your laboratory computers from home and other sites, as well as for running graphical programs (depending on your local operating system).

An SSH gateway is an externally accessible computer that can be accessed by ssh (see table below); once connected to the gateway you can use ssh to connect to other workstations in your laboratory.

Data processing should not be done on the gateway, for computational jobs connect through gateway to another workstation and run your jobs there (for exceptions see Table I).

ssh to:

• crystal.harvard.edu

You should only use crystal.harvard.edu if you have told to do so by SBGrid staff.

Example syntax for connecting to SSH gateway for Harvard Medical School groups:

• Non-GUI connection: 

ssh username@crystal.harvard.edu;

• GUI (connecting to a linux system): 

ssh -Y username@crystal.harvard.edu;

ssh -Y abacus (replace abacus with the name of your workstation.)

• GUI (slower network connection): 

ssh -Y -C username@crystal.harvard.edu;

ssh -Y -C abacus; (replace abacus with the name of your workstation.)

ssh is usually installed by default on linux and OS X systems. Terminal App can be found in your Applications/Utilities folder (when connecting with ssh -Y on OS X systems, X11 will start on its own if necessary).

Please note that external SSH access is deactivated by default. Please contact help@sbgrid.org to request remote access for your account.

Table I

SSH Gateways are enabled in some of the CMCD laboratories. That means if you are outside of the Lab you can SSH to your lab's network using the SSH hosts listed below:

If your site is not included on this list please contact us for further info about remote access.

Labs	Gateway	Running jobs on gateway
HMS and CHB	crystal.harvard.edu	not allowed
DFCI labs	crystal.harvard.edu	not allowed
MCB	galactica.mcb.harvard.edu	allowed

MCB: You cannot ssh to galactica.mcb.harvard.edu if you are inside the MCB or Harvard University network. Instead ssh directly to the system you need to access.

Tufts systems use a VPN instead of a SSH gateway for SSH access.