Xen

I'm currently (may/june 2006) doing some research on the usability of ASE and Replication Server with Xen virtualization (http://www.xensource.com) on Linux systems. Some quick notes:

• ASE 15.0 works OK but sofar only limited tests have been performed.
• Replication Server 15.0 is a problem. It seems that the problem is related to "thread-local storage" (see http://en.wikipedia.org/wiki/Thread_Local_Storage). For performance reasons Xen does not use the standard libraries located in /lib/tls but uses it's own mechanism to handle thread-local storage. For a user of replication server it appears that stable devices cannot be created (in fact only a single 16Kb allocation is done). Research is now focussed on the impact of using thread local storage from /lib/tls in combination with Xen and it's performance impact.
• I'm using Xen version 2 but according to the Xen documentation the issue with thread-local storage is also present in version 3.

Feedback on this subject is very welcome. mailto:peter@petersap.nl