Using Citrix
The Citrix Farm (Citrix), is a centralised series of servers that allow you to run computational tasks remotely, in a user-friendly environment, without slowing down your local PC.
Opposite to a Linux/Unix Cluster, where a series of servers works "in parallel" (i.e. share their CPU as if it were a single system), by connecting to a Citrix Farm you are automatically assigned to the first free server of the series or to the machine with most available resources.
From then onwards, you will use the full power of the resources which have been assigned to you by the centralised system and can start using the applications right-away. This approach is tipically called "Interactive" or "Interactive (Mode)".
The main advantages of a Citrix Farm, compared to a Linux/Unix Cluster, are:
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User-friendly GUI (Graphical User Interface) based on Windows operating system: run remote applications exactly as you would locally on any EUI desktop PC.
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Jobs run "at once" (interactively), that is are not on queue like on a parallel cluster.
Starting a Citrix Session
On Windows-based EUI desktop PCs, you can run Citrix applications as if they were locally installed on the machine [1] [2] :
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Once logged into a machine, double click the Citrix Farm shortcut on the desktop (or use the Start menu alternatively):
Figure 1: Desktop shortcut to the Citrix Farm
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The system will begin to authenticate you on Citrix with the same credentials used to login onto the computer:
Figure 2: Authenticating user on Citrix
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Once authenticated, in order to start the Applications available on Citrix, identify the blue circle Citrix icon on the taskbar (bottom right corner of the desktop - you may need to expand the taskbar by clicking on the small, white upwards-pointing arrow):
Figure 3: Citrix traybar icon
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Click on the icon once to expand the Application menu (note that available applications may vary depending on the user) then select the application you want to run by clicking on it once:
Figure 4: Citrix application menu
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Right-clicking the same icon, instead, open a series of commands which might be useful in case no applications show up (Application Refresh), you want to force reconnection (Reconnect Online Sessions) or you wan to to change startup options (Options):
Figure 5: Citrix commands menu
Please note that if you had any application disconnected from previous Citrix working sessions (e.g. via Web Interface ), even when logging into Citrix via an EUI desktop, you will still be able to pick up from the exact point of where you left. Any previously disconnected application will opne up automatically once you launch Citrix: should this not happen, just righ-click on the blue Citrix icon and choose "Reconnect Online Sessions".
Citrix can be accessed off-campus and/or from a computer other than an EUI desktop PC (e.g. your personal laptop or an EUI Mac) via internet using most common web-browsers (although Internet Explorer is highly recommended).
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To start (or re-connect to) a Citrix session just point your browser to the Citrix Web Interface available at:
https://citrix.eui.eu/
(the link is available as well under the Quick Links section of the CS Homepage or under the Remote & Parallel Computing menu)
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You will be asked for your (EUI) Username and Password. Fill in the fields accordingly:
Figure 6: Citrix Web Interface login screen
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Finally, you will get to the list of Applications available to you:
Figure 7: Citrix Web Interface application list
Please Note: the list of applications shown in the screenshot above may be different from one user to another.
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Unless you changed the setting in the Options menu (or Preferences on the Web Interface), any disconnected application will open up automatically once succesfully logged in.
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You can start any of the available applications by clicking (once) on its icon, a small window with the loading progress will show up:
Figure 8: Application starting
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(via Web Interface only) Depending on the application you may also be asked to choose the Security Level. Select "Full Access" and "Never ask me again":
Figure 9: Choosing access level
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Use your application as you would locally on any EUI PC:
Figure 10: Application started
If you need to open or save files, do as you would locally on your computer: your Private Storage Area (Drive G:), and other commonly used network drives [3] , will still be mapped under Citrix. Use them as you would normally to load or save jobs:
Figure 11: List of available drives (may differ from user to user)
IMPORTANT: Your working directory (input/output folder) should point to your G: Drive (or any subfolder within) or else when disconnecting from Citrix the server will be unable to access your local folders. Setting the working directory is tipically done directly from inside the application and/or by correctly programming your job.
Please Note: if you need help using any of the available research applications (for example to set the working directory), contact the relevant Research Software Tutor .
If your job needs to access a large set of files (i.e. a dataset) which does not fit onto G:, it still should be stored remotely on Citrix and NOT on your local drives, or else once you disconnect, Citrix will be unable to reach it.
A dedicated area on Citrix is available as "storage$ (S:)" drive specifically for this purpose: use it to upload your large data directly onto the Citrix Farm's servers.
WARNING: The S: Drive is a common drive accessible by ALL Citrix users with full read/write rights. Anybody connecting to Citrix will be able to read, modify and even delete your data!
If you are accessing Citrix from a non-EUI PC (i.e., from your personal laptop), in order to copy/move data from your computer to Citrix and viceversa, please consider the following:
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Mac / Linux users: in order to move/copy files across your local computer/hard disk and Citrix, you will have first to
map your Personal Storage Area G: . Once you have access to G:, use
Finder to move/copy files among drives as you would normally.
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Windows users: in order to move/copy files from your local computer/hard disk onto the G: or S: drive, use the Citrix application Explore Xen: local disks will be shown with their usual drive letter followed by a $ symbol, for example C$ on ‘Client’ (see picture above). Use Explore Xen as you would normally with Windows Explorer.
Closing Your Citrix Session
Once your job is running, you may Disconnect from Citrix while letting the application run remotely or, if the job has already finished, you may close the application and Log Off from Citrix (thus freeing up resources for other users):
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To disconnect from Citrix on EUI desktops, right-click on the Citrix icon in the traybar and choose "Disconnect Online Sessions":
Figure 12: Disconnecting from EUI Desktop
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To disconnect from the Citrix Web Interface, click Disconnect from the top menu:
Figure 13: Disconnecting from Citrix Web Interface
Please Note: if you disconnected from Citrix while keeping an application running remotely, next time a Citrix session is started (both via EUI desktop or online via Web Interface ), you will be presented directly with the open application and its results (if any).
If, instead, your application has finished, close the application (tipically via File Exit or File Quit - but may vary depending on application) and Log Off from Citrix:
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To log off from Citrix on EUI desktops, right-click on the Citrix icon in the traybar and choose "Exit":
Figure 14: Logging off from
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To log off from the Citrix Web Interface, click Log Off from the top menu:
Figure 15: Logging off from Citrix Web Interface
IMPORTANT: please be sure to close/quit all applications whenever not used as this allows resources to be freed up for other users!
= Users with an EUI desktop PC running a Staff Configuration should contact their local IT User Support (Site Office) for first activation.
= Users with an EUI desktop Mac (iMac) should follow the Off-Campus documentation instead.
= Drives normally available within your Citrix applications:
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Local drives: drives on the local computer may have their drive letter re-assigned under Citrix but can be easily identified as they will be called 'x$ on Client' followed by the newly assigned Citrix letter (where x = local drive letter), i.e.: C$ on 'Client' (T:). would be the local drive C: re-assigned in Citrix as T:.
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G: drive and other user's personal areas or network shares: will show up with their usual network name and drive letter (as on any EUI desktop PC), i.e.: jsmith on 'ressrv1' (G:) or common on 'ressrv1' (H).
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S: drive (Storage on Citrix): Citrix server's storage area (used to save large datasets) will show up as storage$ on 'vspsrv1' (S:).