In association with the XenApp 5 release and inline with the product release strategy outlined in the Future of XenApp for UNIX blog article, the XenApp for UNIX 4.0 with Feature Pack 1 release is now available as a MyCitrix download. This is a small feature pack containing the following changes:

• XAU Rebranding: Look and Feel of the product had been changed to align with the general XenApp rebranding. This primarily affects the login screen and all icons used when interfacing with ICA clients, WI and PNA.
• XAU MOTD (message of the day): Adds the ability for administrators to place a message in the file /var/CTXSmf/motd, the contents of which are displayed as text in a message box on the screen before the user logs in.
• XAU NOMORELOGIN: Adds the ability for administrators to disable any new logons to a server by using the ctxcfg -k nomorelogons=1 keyword configurable. Users can still reconnect to any disconnected sessions. At the next restart of Citrix Presentation Server for UNIX this behaviour is reverted.
• As well as the above, a number of bug fixes are being released: 
  • Fixes an issue where the ctxfm process can crash if an authentication time-out is enabled. 
  • Fixes issues where replacing a non-retail license with another license can cause the ctxfm process to consume large amounts of CPU. This occurs if the license is changed but the Citrix Presentation Server processes are not restarted. 
  • Adds the ability to disable scrollmouse support. This uses the ctxcfg -k disablescrollmouse=1 keyword configurable to make a server session not claim this capability. Add the option -noscrollmouse to the XTW_OPTS line in /opt/CTXSmf/slib/ctxXtw.sh to turn off the X server's capability to handle any scrollmouse events that the client sends. 
  • Fixes an issue where errors could be generated when parsing XML Service packets under rare network-related conditions (for example congestion and misconfigured hubs or switches). 
  • Fixes an issue where the X server could crash when multiple OpenGL applications are run at the same time. 
  • Fixes an issue where screen corruption could occur when scrolling window contents. 
  • Fixes an issue that meant users had to re-authenticate when connecting to a published application using Web Interface 4.6. 
  • Fixes an issue where shadowing highly graphical applications could cause screen updates to lock up for all sessions involved.

• License Server: New release at the same release level as the Windows License Server.  As well as a re release for the Solaris SPARC platform, support on the Solaris x86/x64 platform has been added. As well as being included with the XenApp For UNIX with Feature Pack 1 download it can be downloaded separately as License Server 11.5 for UNIX.
• Updated Administration Guides for this XAU Feature Pack and the Licence Server product.

An associated public hotfix for each supported platform is also available (PSE400AIX054, PSE400HPUX054, PSE400SOL054, PSE400SOLX54). By default this contains all the bugfixes in Feature Pack 1. You can also configure the hotfix to upgrade your installation with Feature Pack 1 changes where your upgraded installation will then require licenses that provide Subscription Advantage Eligibility Dates for all platforms of August 27, 2008. This corresponds to installing the XenApp for UNIX 4.0 with Feature Pack 1 release.

Private and public hotfixes going forward will be common and applicable to all releases which makes patching simpler.

As a follow up to Sridhar's post about Future of XenApp for UNIX I'll like to dig a little deeper on what options there are for publishing Linux applications and desktops though the existing Citrix UNIX product offerings.

There are a variety of methods on how this can be achieved and they are all generally variations on the use of XAU/CPSU as a broker to serve the Linux applications/desktops to ICA clients from the environment they are run in.

The simplest way to achieve this is to use separate Linux servers to run the applications/desktops and publish the mechanism to access these on the XAU/CPSU server. Any of the existing platform versions of XAU/CPSU (Solaris x86/x64, Solaris SPARC, AIX POWER or HP/UX PA-RISC) can be used in this method. The publishing mechanism is commonly a shell script that uses remote shell access (eg rsh, ssh) which is made easier if network user accounts are available but this is not a requirement. Other things to think about is session load balancing, if a multi-server XAU/CPSU farm is used to broker session there are advantages to tying individual Linux servers to particular XAU/CPSU servers. If there are differences in the performance characteristics of the Linux servers this can be evened out through XAU/CPSU load balancing tools.

A variation of the above is to make use of Solaris 10 x86/x64 Linux Container technology. This is a capability introduced in Solaris 10 where Linux applications are run in a Linux container on the Solaris 10 system. A Linux Container is effectively a Solaris kernel with Linux kernel interfaces (system calls, /proc, etc) with standard Linux distribution user-land components (utilities, etc) and Sun claims a high-level of binary compatibility with Linux distributions. In this variation XAU/CPSU can be installed on the same Solaris 10 x86/x64 server that hosts the Linux Container and through shell scripting mechanisms already mention access to the Linux applications/desktop can be achieved. Now that Solaris 10 x86/x64 is officially supported on HP, IBM and Dell hardware as well of course on Sun's own x86/x64 hardware there is a range of hardware vendor supported options here.  

Another variation is the use one of the x86/x64 server virtualization solutions to virtualize both the XAU/CPSU and Linux servers. The requirement here is the support for both Solaris x86/x64 and Linux x86/x64 virtual machines. The example below shows how it might be achieved with XenServer virtalizing Linux and Solaris 10 servers once Sun completes their paravirtualized kernel and drivers. However, any other server virtualisation technology that can virtualize the Linux and Solaris servers can be used to provide a similar solution.
 

 

Options in this area are appearing all the time and and some may well warrant investigation.  One recent announcement from Transitive offers capabilities to run Solaris SPARC binaries on Linux x86/x64.
 
So I hope I have shown there are ways to architect a solution to publish Linux Applications/Desktops with existing XAU/CPSU offerings but do please do tell us what you think.