An explanation on Thin Client technology
What are Thin Clients?
Typically, thin Clients are low powered computers that (strictly speaking) do not have a hard disk drive. Since there is no hard disk drive, there is also no operating system. And since these are low powered systems, all processing is done on the server instead of the thin client itself. Certain types of thin clients (running on Windows Embedded Standard 7 (WES7) or Windows 8 Embedded Standard or even Linux embedded) may have full fledged OS capabilities complete with installed applications such as Microsoft or Open Office and browsers such as Internet Explorer and/or Mozilla Firefox.
If there is no hard disk drive and no operating system, how does it work? How does it boot up?
Thin Clients may boot either directly from the server via PXE boot (which is rarely done these days) and then connect to a terminal server or boot up from a local flash running Windows XP embedded, Windows Embedded Standard 7 , Windows 8 Embedded Standard, Windows CE or a Linux embedded OS and then connect to the server. Once connected to the server, the user gets the log in screen of the operating system running on the server.
Please bear in mind that booting from a server and connecting to a server are two different processes, since you can have more than one server – one simply for booting up and the second or even a third or more for connecting to (where the applications are installed and processing takes place) depending upon architecture. If required, an enterprise can also go in for a hybrid architecture consisting of both Windows and Linux Terminal servers.
Where are the various applications installed and user data stored?
All applications are installed on the connecting server and every user has his own “My Documents” folder created where his profile, documents, etc. are stored.
If all files and documents of all users are stored on the same server on the same storage device, can one user not access or read the files of another user?
As stated above, every user has his own “My Documents” folder created. No user can access or even get into another user’s “My Documents” folder unless specifically permitted to do so. This of course, will require an NTFS file storge system and not the FAT32.
What kind of applications and software can one install and run in a Thin Client environment?
All programs of everyday life can be used with Thin Clients… to name a few MS Office; various various browsers for surfing; e-mail clients like Outlook Express, Microsoft Outlook, etc.; ERP packages – including SAP; Coreldraw, Adobe Photoshop, Pagemaker, Tally, MS SQL based packages, chatting (using keyboard) programs and even open source and customized packages.
Which software packages cannot be used?
Heavy graphical games, animation packages like Maya and such others that require a very fast screen refresh cannot be used.
How many Thin Clients can be made to run on a single server?
This depends upon the server hardware configuration, the choice of operating system and the programs/applications that are installed on that particular server. Typically, a small office with 10 Thin Clients can be well served by an entry level server with a Xeon Quad Core 3.1 GHz processor and 2GB (recommended 4GB of RAM).
For users on an enterprise level, a server with dual or more Quad core or Hexa core processors, a minimum of 8/16/32GB RAM (depending on the numbers of users) and redundancy on storage devices by way of RAID, network adapters and power supply unit is recommended. Load balancing and fail over technologies with additional servers can be used to prevent any single server from reaching critical levels.
These are of course, broad guidelines. Actual server hardware and architecture will most definitely vary from case to case.
Can one install a printer on a Thin Client?
Yes. Most printers can be installed on a Thin Client node either on a parallel port or USB port. The printer is physically installed on the Thin Client node but in configured on the server as a local printer printing to a TCP/IP port. In case of embedded systems, the printer in configured locally on the Thin Client itself.
What devices can a Thin Client access locally?
Most devices like hard disk drives (external/portable), pen drives, floppy disk drives and optical drives can be accessed by a Thin Client without any problem. For other devices like scanners, multi function devices and CD/DVD writer, if required on a Thin Client, our embedded systems are recommended, one that is running a Windows embedded OS.
Will ‘Touch Screens’ work with Thin Clients?
Yes, very much. Both with Windows and Linux embedded.
What about Thin Clients and Citrix?
With Citrix receiver installed, both Windows and Linux embedded thin clients can access a Citrix server.