Now a days Enterprises are looking to increase server utilization with minimizing server farm and reduced total cost of ownership (TCO).The Xen is an open source hypervisor technology which enables to create multiple server environments on single hardware. Running SAP on Linux under Xen, offers with flexibility and may help you to reduce TCO.
SAP and Xen
Looking at future’s need SAP started supporting Linux under Xen virtual machine back in December 2007.
Currently two Linux distributions RedHat and SuSE are certified for Xen Virtualization , But on IA64 processor architecture only RedHat is certified.
Right Now we can use only Xen para-virtualization , full-virtualization is currently not supported by SAP.
Deploying SAP on Xen VM
SAP strongly advice us to put Xen virtual machine on raw device or partition to get desired I/O performance also advices to use external storage for Virtual Machines.
While deploying Guest operating system on Host OS , SAP recommends to use same distributions; But practically we may need to use some other distribution or OS, here SAP supports the installation if guest system is already certified by SAP with out supporting the third party applications like Database.
As per the SAP Lab test result overhead of the host OS i.e. Xen virtualization layer is less than 15 %.