37 PowerEdge R820 Technical GuideSupport of the operating systems listed in Table 21 is limited to a virtual environment as a guestoperating system. Please contact the software vendor for additional support or questions aboutrunning the operating system in a virtualized environment.Table 21. Virtual guest operating system supportOperating System Platform EditionMicrosoft Windows 2003 x86 WebMicrosoft Windows 2003 R2 with SP2x86 StandardEnterprisex64StandardEnterpriseData centerSupported virtualizationOne of the key features for virtualization on the PowerEdge R820 is the support for a fail-safehypervisor. By running a hypervisor on an optional SD card and installing a backup copy on theother mirrored SD card, you can protect against hardware failure and maximize virtualization uptime.Table 22 highlights the virtualization support for the R820.Table 22. Virtualization supportOperating systems Install version FactoryoptionsInternal dual SDmodule installsupportVMwarevSphere v5.0 ESXi DIB YesvSphere v5.0 U1 ESXi DIB YesvSphere v5.1 U1 ESXi DIB YesvSphere v5.1 ESXi DIB YesvSphere v5.5 ESXi DIB YesCitrix XenServer 6.1 N/A DIB YesRed Hat1 Enterprise Virtualization 3.1 N/A DIB NoFI = factory install; DIB = drop in box1No OpenManage support; drop-in-box license registration card only