SAP Basis Tech Supports

Symptom
You want to use one or more virtual host names for SAP software within an SAP server landscape to hide the physical network identities for the pieces of software from each other.
This type of installation may also be useful when moving SAP servers or complete server landscapes to other new hardware within a short time frame without having to carry out a reinstallation or complicated reconfiguration.
Other terms
Virtualization,system copy, system cloning
Reason and Prerequisites

You require a new static IP address for each Virtual Host Name.The steps described below apply only to SAP server software based on SAP NetWeaver.
Solution

To decouple the SAP servers securely and permanently from their physical network identities (TCP host name + IP address), you require a new network identity for the SAP system which consists of a new host name and a new IP address( static) .
The SAP system is installed in the physical server with this new network identity ( Virtual Name). If required, you can move this SAP System installed with the SAP server software and its configuration to new hardware.
We recommend that you avoid using TCP alias names within a server infrastructure (see below). Since this new network identity will no longer be bound to the physical hardware, it is referred to as a “virtual” network identity.

RESTRICTIONS:
1. Do not use any TCP network alias names to virtualize physical host names within the intra-server communication. This is due to the host name and IP address resolution that is sometimes executed repeatedly by server applications, and which usually results in the actual physical host name instead of the virtual name. Refer to Note 129997.2. SAP does not support to use Local Users to install an SAP system in a distributed environment.3. Installation of SAP system ( Central system) with a virtual hostname using Local Users is not supported for SAP releases 7.00, 7.01 and 7.10.
If Local Users are used to install a second instance of the same SID ( for example: Java Stack addin), then the SAP installation fails with errors. These installation errors are fixed in the Installation Masters DVDs for SAP Release 7.11 (PI).
Procedure to install an SAP system with a Virtual Host Name

( IMPORTANT: The procedure described below is NOT for MSCS Cluster Installation: To install an SAP System in MSCS environemnt, please follow the relevant installation guide for your release )
1. Assign Static ip-address to the server( Primary Host Name)2. Create the registry entries as specified in the OSS Note #3605153. Add new ip-address to the NIC (for the Virtual Host Name).
Windows 2003:
Go to Start–>
All Programs –>
Control Panel –>
Network Connections–>
Properties ( For the correct Network Card) –>
Cick on Internet Protocol (TCP/IP) –>
Properties –>
Advanced –>
Windows 2008:
Go to Start–>
All Programs –>
Control Panel –>
Network and Sharing Center –>
Manage Network Connections –>
Properties ( For the correct Network Card) –>
Cick on Internet Protocol Version X (TCP/IPvX) –>
Properties –>
Advanced –>
Add a new Ip-address in the IP-address section of tab IP Settings
Use the same subnet mask as the Primary Host Name
( Note: The Add option will be grayed out if DHCP address is used
for the Primary Host name )
4. Maintain the ip-address in the Hosts file of the system where this Virtual Hostname is created. Maintain also in the DNS Server so that you can connect to this virtual system from other clients using SAP GUI.5. Reboot the Server6. Start the SAP installation in the command line with the command “sapinst.exe SAPINST_USE_HOSTNAME=<Virtual Host Name>”

TROUBLESHOOTING

An error occurs during the second instance installation of a SAP system on the same host using the virtual host name. This occurs only when local users are used to install the SAP instances. The SAPInst dev log contains the following log entries :
WARNING[E] 2008-11-19 16:23:21.012 [synxcgroup.cpp:435]
voidCSyGroupImpl::addMember(PSyAccount pAccount) FSL-01006
Unable to add account <Primary_Hostname>\SAP_AA5_GlobalAdmin
to group <Primary_Hostname>\SAP_LocalAdmin.
A new member could not be added to a local group local group
because the member has the wrong account type.
SOLUTION: open the keydb. xml to set the status ‘OK’ and continue the installation with the option ‘Continue with the old Installation”
An error occcurs in the service creation phase during the second instance installation of a SAP system on the same host using the virtual host name. This error occurs only when local local users are used to install the SAP instances The SAPinst dev log contains the following log entries:
WARNING 2008-11-19 16:28:13.832 CJSlibModule::writeWarning_impl()
Execution of the command “H:\usr\sap\AA5\D07\exe\sapstartsrv.exe
-r -q -p \\vsystest3\sapmnt\AA5\SYS\profile\START_D07_vsystest3
-s -n 07 -U vsystest3\SAPServiceAA5 -P XXXXXX -e vsystest3\aa5adm”
finished with return code -1. Output:
Cannot install service.
CreateService failed: 421
The account name is invalid or does not exist, or the password
is invalid for the account name specified.
SOLUTION: open the Keydb. xml and change the following lines:[<virtual_hostname>\SAPService<SID> ] TO
[<primary_hostname>\SAPService<SID>][<virtual_hostname>\<sid>adm] To [<primary_hostname>\<sid>adm]
Restart the installation from the command prompt with the
option ‘Continue with the old Installation”