Remote desktops
One of Strudel's key features is to allow you to run a remote desktop on M3 hardware. You can access the desktop directly from your browser, meaning you do not need to install any extra software. You can choose whether to use a particular GPU, or stick to a CPU-only desktop when you do not need to run intensive graphics applications.
Usage
Click on the Desktop tab in the left sidebar.
You should see something similar to the screenshot below.
The different sections are:
| Section | Purpose |
|---|---|
| Instructions/Description | Used for basic information/alerts. |
| Launch desktop | Configure and launch a new desktop session. |
| Pending/running desktops | List of pending and running desktops. You use this to connect to a running desktop. |
| Completed desktops | List of completed desktops. You can view/remove each session's logs. |
Starting a desktop
First you must configure the desktop that you want. This is in the Launch Desktop section. The input fields from top to bottom are:
| Field | Comment |
|---|---|
| Operating System | Ensure this is set to Rocky 9. |
| Time | Maximum time limit for your desktop. |
| GPU/CPU | Select a type of GPU you want, or No GPUs if you are running CPU-only workloads with minimal graphics. |
You can optionally check Advanced Options to have full control of the underlying sbatch command submitted by Strudel.
See Specifying resources in Slurm.
Once you are happy with your configuration, click the Launch button.
Once you have clicked Launch, your job should shortly appear in the "Pending/Running desktops" section.
After some time, your desktop should start, as indicated by its RUNNING state in the left column.
Once it is running, click Connect on the right hand side.
You should see a progress bar appear saying Getting app parameters . Wait a few seconds, and a new tab should
open in your browser showing a noVNC splash screen.
If a new tab didn't open, it may be because you need to enable pop-ups/redirects for Strudel in your browser. Your browser should have notified you of this.
If an error occurred, you should see an error alert at the bottom of the screen. Please contact our help desk with the contents of this error as well as the exact steps you took that led to the error.
Click Connect in the noVNC screen
When you click Connect in the noVNC splash screen, you may see a red error message appear at the top of your screen
saying "Failed to connect to server". If so, just close the noVNC tab and try connecting again in Strudel. If you keep
getting this error, try cancel your desktop and launch a new one. If the issue persists, contact our help desk.
You should now see a desktop in your browser!
Using a desktop
We won't detail all possible actions you can take on a desktop, but here are some things to note.
Click on "Applications" in the top-left corner to see a categorised list of applicatons that you can launch.
In the top toolbar, you should also see icons for:
- File browser
- Terminal
- Firefox (browser)
In the middle-left of your screen, you should see a handle for a collapsed sidebar.
Click on this to expand the left sidebar.
The most useful button is the clipboard, which lets you copy and paste from your host computer into this remote desktop. Here, "Host" just means your normal computer outside of the remote desktop.
| Copy from | Paste to | How? |
|---|---|---|
| Host | Remote desktop | 1. Copy the text in your host. 2. Paste that into this sidebar clipboard. 3. Inside the remote desktop, you can paste. |
| Remote desktop | Host | 1. Copy the text inside the remote desktop. 2. Verify this text appeared in the sidebar clipboard. 3. Select and copy the text in this clipboard. 4. Paste in your host. |
Closing a desktop
Simply close the desktop's tab in your browser. If you still have Strudel open, you will see an alert.
Click Terminate desktop to permanently end the desktop session, or Leave it running if you wish
to return to this desktop later.
Please be mindful of leaving a desktop running idle. This holds up resources and will mean other users will have to wait longer to access resources. Be considerate of others!
Cancelling a desktop
In the Strudel desktop portal, click on Cancel next to a running desktop in "Pending/Running desktops".
Troubleshooting
If at any time you get an error alert like below, first read the error message. If it doesn't make sense to you, please contact our help desk with:
- The full contents of this error. Please copy-paste it rather than sending a screenshot.
- The exact steps you took that led to the error.
Viewing logs
Every running and completed desktop has a View log button. Click this to open a new tab showing that desktop's log, which may
contain useful messages explaining what went wrong.
I can login to Strudel and launch a desktop but cannot connect. I click the connect button and get an error saying "failed to connect to server"
This can happen if you run the command conda init. This modifies your ~/.bashrc file in your home directory.
To see how to resolve this issue, please see this note in our Conda guide.
This can also happen with other changes to the ~/.bashrc file, so care has to be taken if you wish to modify the file!
Specifically, any command in ~/.bashrc that prints output to stderr can cause Strudel desktops to break.
Could not connect to session bus
When you try connecting to a Strudel desktop, if you see a message like:
Could not connect to session bus: failed to connect to socket ...
then you almost certainly have some conda initialisation code in your ~/.bashrc.
See the section above.
Strudel crashes when trying to connect to desktop
This is a common result of a full home directory. Strudel uses your home directory to
store small temporary files and logs, and if your home directory is full, it can’t do
so and fails to start desktops. To resolve this, SSH into M3
and run the command user_info.
This will tell you if your home is over quota.
I can connect to a Desktop, but the display looks messed up, or I can see the display, but cannot interact with the Desktop!
This may be fixed by moving or clearing the hidden directories in your home directory: ~/.cache and ~/.config. To see them,
use the ls -a command in your home directory. Try moving them to see if it fixes your desktop display issues by running:
mv ~/.cache ~/.cache.bak
mv ~/.config ~/.config.bak
If this resolves your display issue, you can remove the old directories with the command rm -rf ~/.cache.bak ~/.config.bak.
I’m unable to type certain letters in Strudel web desktop
If you are using Safari as your browser, you may find that you cannot enter some keys, such as s, d, e, and f. The solution seems to be to use a different browser, e.g. Chrome or Firefox. See this forum for similar complaints.