Configuring the system for the SAP HANA workload

After you deploy IBM® Power Systems™ Virtual Server, the following needs to be done within the operating system.

1. Configure root user access. You can log in to the system as a root user by using a configured SSH key. Logging in as a root user with a password through SSH is deactivated. You can log in as a root user by using the default password root in a virtual console window. After you log in, change the default password for the root user.
2. Start and enable the multipath deamon, for example, by running systemctl start multipathd and systemctl enable multipathd.

3. Set jumbo frames for network adapters. Jumbo frames is another way of saying network maximum transmission units (MTU) of 9000-byte payload frames. All the network components in IBM Power Systems Virtual Servers support jumbo frames. In cases where certain network components don't support jumbo frames (for example, in communication to the external world), setting MTU=9000 can cause network issues. Therefore, set MTU=9000 only on adapters that are used internally.

   You must set jumbo frames on private networks that are used for communication between multiple instances in SAP three-tier systems as follows:

   # cd /etc/sysconfig/network
   # vi ifcfg-ethX <--- name of ethernet device used for communication between SAP instances
   BROADCAST=''
   ETHTOOL_OPTIONS=''
   BOOTPROTO='static'
   IPADDR='xx.xx.xx.xx/xx'
   NAME='Virtual Ethernet card 0' NETWORK=''
   REMOTE_IPADDR=''
   STARTMODE='auto'
   USERCONTROL='no'
   MTU='9000'
   

   To activate the changes, restart your network (ifdown ethX; ifup ethX), or set the MTU for the current configuration (with ip link set dev <ethX> mtu 9000).

4. Verify hostname resolution. Check that the DNS server is correctly entered in /etc/resolv.conf and that instance hostname resolution is possible (in the simplest case, through an entry in /etc/hosts).
5. Synchronize time. Ensure that the IBM Power Systems Virtual Servers that belong to the same SAP system have their time synchronized. For example, connect you partition to the time server with ntpdate -u <ntpserver>.
6. Tune SUSE Linux® Enterprise Server for the SAP HANA workload. On IBM Power Systems Virtual Servers, the same SUSE Linux® Enterprise Server image is used for SAP NetWeaver and SAP HANA. Run the following command to tune the operating system for the SAP HANA workload: saptune solution apply HANA. Enable the tuning daemon by running systemctl enable tuned.
7. Prepare file systems on additional storage volumes. If you attached additional storage volumes to your IBM Power Systems Virtual Server, you must create file systems by using Linux Logical Volume Manager. For an example, see Create file systems on SLES12 SP4 by using the command-line interface.
8. Register your SAP virtual server by SUSE. Register your IBM Power Systems Virtual Servers by SUSE (for example, via SUSE RMT server as described in the SUSE documentation).