update

This site provides information on the services provided by the SBGrid Advanced Research Computing Group (ARC) at Harvard Medical School. The SBGrid ARC provides Research Computing Systems support to SBGrid ARC Member Labs.

See the [SBGrid Website](https://www.sbgrid.org/)

## Help

* [Getting Help & Support](faq-getting-help)

[[include:faqs]]

In general x2go is easier to use and sufficient for most scenarios. Xpra has better performance and uses less resources. Both clients connect through ssh and are generally faster than ssh -Y. Support for these is beta, x2go is more familiar to the support staff. Most linux systems do not have these tools installed, so you may need to request them.

We recommend using x2go. x2go is more familiar to the support staff and it is easier to use.

x2go can be downloaded from this page.

* <https://wiki.x2go.org/doku.php/download:start>

#### Additional Steps

You will need to open System Preferences - Security - General - Temporarily 'Allow from anywhere' open the application, make sure you can reopen it. Then change your security setting back to 'App Store and Identified Developers'

x2go requires XQuartz - see [faq-using-sbgrid-programs](faq-using-sbgrid-programs) if you do not already have it installed.

Create a new session

Make sure you fill out the following -

1. host - the host that you want to connect to.

2. login - your username

4. Session type - Mate

You can adjust the resolution after the session has started.

xpra has been described as 'tmux for X11'. It uses x264 encoding.

#### OSX to Linux workstation usage

For Mac OSX newer than 10.9 the installer is on their downloads page

GUI version -

For command line usage please us the 'pkg' installer located here -

#### xpra gui

On remote system - copy xpra-launch.sh to your home folder and ./xpra-launch.sh or useone of the lines below.

#### Full desktop

tmux new-session -d -s "xpra-desktop" "xpra start-desktop --start=mate-session :$((10 + RANDOM % 999)) --pulseaudio=no --daemon=no"

#### Minimal termial window

tmux new-session -d -s "xpra-terminal" "xpra start --start=mate-terminal :$((10 + RANDOM % 999)) --pulseaudio=no --daemon=no"

#### open xpra gui

Select mode ssh - enter username, host and password info. If there is only one xpra session it will automatically connect to it. You can also save that info to a config file and launch that after.

To end the session on the remote system either tmux a and Ctrl-c or 'xpra stop'

On your local Mac OSX system open a terminal window and run

`xpra start ssh/oconnor@sch-boltzmann/42 --start-child=xterm`

To disconnect, just ^c from the original terminal window(not the xterm that you connected to), or if you connect from another system it will automatically detach.

reattach to attach -

Note the number 42. You need to pick a number that someone else on the system is not using. Do not use a low number that could be inuse by the system like 0 - 5, instead pick a higher number up to 999.

`xpra stop :666`

xpra at :666 has exited.

`xpra start ssh/oconnor@sch-boltzmann/42 --start-child=xterm --window-close=shutdown`

For all systems off of the sbgrid network it will be easiest if you use the [cmcd-vpn](faq-connecting-to-cmcd-vpn).

Ideally you would have already set up [SSH with keys](faq-setting-up-key-based-ssh)

Press enter one time - is it waiting for password input?

`xpra list`

If there is an active session you can connect to it via `xpra attach ssh/user@host/42' from your client.

'xpra stop :42`

Try to launch a session from the host in a tmux or screen session on the remote server -

`tmux`

`xpra start :617 --daemon=no --start-child=xterm`

You should see a line that that contains `xpra is ready.`

Frequently Answered Questions

* [Change Your Unix Password](faq-changing-your-account-password)

* [SBGrid/CMCD VPN](faq-connecting-to-cmcd-vpn)

* [Requesting an Account](faq-new-accounts)

* [EM Systems Access](faq-em-facility)

* [Access Remote Filesystems using SSHFS](faq-sshfs)

* [Linux Remote Access](faq-remote-access-to-linux-computers)

* [OS X (Apple): Find MAC Address](faq-how-to-find-mac-address-on-os-x-gui)

* [Running jobs after you logged off (using Screen)](faq-running-remote-jobs-after-disconnecting)

* [SSH with keys](faq-setting-up-key-based-ssh)

* [SGI Dial Box on Linux](faq-dial-boxes-on-linux)

* [Other Resources](faq-other-resources)

* [Data Collection at NE-CAT](faq-data-collection-at-ne-cat)

* [SGM EM Facility](faq-em-facility)

* [Moving Data](faq-moving-data)