Remote Access to Linux Computers

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

SSH

Request External SSH Access

Please email help@sbgrid.org to request access to external SSH. If we detect that you haven’t used your external SSH in 3 months, we’ll disable your external SSH access. You’ll still be able to login locally and SSH from your workstation in the Lab to others systems that we manage for you.

Overview

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).

How To SSH

ssh to:

• xtal200.harvard.edu

You should only use xtal200.harvard.edu if you have told to do so by SBGrid staff. If you need access please email help@sbgrid.org.

On Apple systems we reccommend using Terminal App, found in your Applications/Utilities folder. Also see SBGrid Software. On Windows systems we know of Xming, vcxsvr, WSL, and MobaXterm. We do not currently support or have a preference for usage.

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

• Non-GUI connection:

ssh username@xtal200.harvard.edu;

• GUI (connecting to a linux system):

ssh -Y username@xtal200.harvard.edu;

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

* GUI (slower network connection):

```bash
ssh -Y -C username@xtal200.harvard.edu

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

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

SSH Gateways

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.

HMS, CHB, & DFCI Labs

ssh to xtal200.harvard.edu. You cannot run jobs on the gateway host and must ssh to your computer nodes to run jobs.

MCB Labs

ssh to galactica.mcb.harvard.edu. You can run jobs on the gateway or on orthus.

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 Tufts VPN instead of a SSH gateway for SSH access.