Interactive Desktop
Opening Interactive Desktop Form
-
The first step is to select the
Interactive apps
and then click theDesktop(XFCE)
in the Open OnDemand dashboard. -
Then you will see a form which needs to be filled to launch the interactive desktop on the compute nodes.

Partition
-
Partitions are work queues that has computational nodes in it to run the jobs. The partitions available in Discovery are
interactive
,normal
,gpu
,backfill
,class
,epscor
,iiplab
,cfdlab
, so on. -
However, you will see only the list of authorized partitions available for your Discovery account and hence, you won’t see the partitions which you don’t have authorization in the select dropdown.
-
Select one of the partitions where you want to submit your job. Refer to the page → Partitions in Discovery to select the ideal partition for your job.
-
By Default, partition is set to
interactive
.
Walltime(Hours)
-
Sets the Walltime for your job. The job gets killed if the Walltime you set gets elapsed.
Parameter #Hours Min Limit
1 hour
Max Limit
24 hours
Default
1 hour
CPUs(Threads)
-
Sets the Number of CPUs(Threads) for the job. The below table shows the maximum limit for CPU threads for each partition. The default and minimum value is 1 CPU thread.
Partition Max Limit interactive
16
normal
44
gpu
28
epscor
124
iiplab
52
cfdlab
52
class
60
Memory (GB/Gigabytes)
-
Sets the memory for the job in terms of GB. The memory you select is available to all assigned threads for the job. The below table shows the maximum memory limit for each partition which can be requested for the job. The default and minimum value is 1 GB.
Partition | Max Memory Limit(GB) |
---|---|
interactive |
64 |
normal |
240 |
gpu |
50 |
epscor |
3000 |
iiplab |
175 |
cfdlab |
175 |
class |
490 |
GPUs
-
To enable the GPU selection, you need to choose one of the following partitions:
interactive
,class
,gpu
,epscor
,iiplab
,cfdlab
. Only these partitions have GPUs and if you select any of the partitions, you can see theGPUs
dropdown enabled.Parameter #GPU Min Limit
0
Max Limit
2
Partition normal don’t have GPUs. |
Email Address
-
If you want to get notified via email when the job starts/fails/ends, enter the email address associated with the Discovery account.
-
You can leave the text field
blank
if you don’t want job notifications.
Launching the Interactive Session
-
Once all the form fields are set, you can click the
Launch
button. The interactive session will be launched and the below output is shown.

-
The above output shows that the interactive Desktop session has been launched successfully. You will see the Launch Desktop(XFCE) only if the resources you have requested becomes available. Else, you might need to wait for some more minutes for the resources allocation and then the Launch Desktop(XFCE) button appears.
-
You can also set the
Compression
andImage Quality
for Interactive Desktop by using the slider. After setting the values, click the Launch Desktop(XFCE) button.
The interactive session won’t be launched if you try to submit your job to the partition that you don’t have access to. You will get the following error message → Batch job submission failed: User’s group not permitted to use this partition. Also, the page gets reloaded and you need to select the value for the form fields again since the form gets reset. |
Opening Interactive Desktop
-
On clicking the Interactive Desktop(XFCE) button, the interactive desktop opens in a new tab through a VNC session.
-
You are provided with
four different workspaces
which is displayed in the top right corner of the window and you can use it.

-
At the bottom of the screen, you will see different options like
Terminal Emulator, File Manager, Application Finder, Web Browser, Minimize windows
which you can make use of it.
Opening applications
-
Click the
Applications
tab in the top left of the screen and you will see the list of available applications.
Output:

Killing the interactive session
-
Click the
Applications
tab and then select theLogout
option. -
Then, you will get a pop-up to confirm.

-
On confirmation, you will be disconnected and the interactive session gets deleted. You will see a similar output like below:

Alternate way
-
Another way to delete the session is to go to the
My Interactive sessions
tab and select theDelete
button of the current interactive session.

Whenever you are done with the work, it’s always recommended to kill/delete the interactive session running on the compute nodes and free the resources. |