Install SAP Instances

Complete the following steps to install the ASCS10 and ERS20 instances on node-a and node-b.

Prepare for Installation

1. On node-a and node-b, increase the available swap space to greater than 1MiB to satisfy the SAP system requirements. In this example we will create a 1GiB swap file to increase the available swap space.

# mkdir /swap
# dd if=/dev/zero of=/swap/swapfile.img bs=1024 count=1M
# mkswap /swap/swapfile.img
# echo “/swap/swapfile.img	swap	swap	sw	0 0” >> /etc/fstab
# swapon /swap/swapfile.img

2. Ensure that the tcsh package is installed on both node-a and node-b. Modify this command (e.g., to use zypper install) if installing on a SLES server.

# yum install -y tcsh

3. On node-a and node-b, create a /sap-install directory which will contain the SAP installation files.

# mkdir /sap-install

4. Download SAPCAR, SAP Software Provisioning Manager 2.0 (SWPM20SPxx_x-xxxx.SAR), and all necessary packages (e.g., SAPEXE_xx-xxxx.SAR, SAPHOSTAGENTxx_xx-xxxx.SAR, etc.) to the /sap-install directory on both nodes. Make sure that SAPCAR is executable.

# chmod +x /sap-install/SAPCAR

5. Use SAPCAR to extract the files for SWPM 2.0.

# /sap-install/SAPCAR -xvf SWPM20SPxx_x-xxxx.SAR

Before installing the SAP instances, verify that all shared file systems described in Create SAP NFS Shared File Systems are mounted on node-a and node-b and that the LifeKeeper resources providing virtual hostname failover for the ASCS and ERS instances are in-service on node-a and node-b, respectively.

Install the ASCS Instance

Complete the following steps to install the ASCS10 instance on node-a.

1. If installing from a remote system, add a firewall rule to allow inbound traffic on TCP port 4237 (the port which exposes the sapinst graphical interface) on node-a.

2. Execute the following command on node-a to initiate sapinst with the virtual hostname associated to the ASCS instance:

[root@node-a ~]# /sap-install/sapinst SAPINST_USE_HOSTNAME=sps-ascs

*Note: The SAPINST_REMOTE_ACCESS_USER=<user> parameter may be used to allow login to the sapinst graphical interface by a non-root user.

*Note: If sapinst displays an error due to a missing dt_socket transport library, install the libnsl package with yum -y install libnsl.

3. To access the sapinst graphical interface, use a web browser to navigate to https://<node-a Public IP>:4237/sapinst/docs/index.html.

4. Select Software Provisioning Manager 2.0 SP XX → SAP S/4HANA Server 1909 → SAP HANA Database → Installation → Application Server ABAP → High-Availability System → ASCS Instance and click Next.

5. Provide the following parameters when installing the ASCS instance. The icon indicates that the default option is chosen.

Field	Value
SAP System ID (SAPSID)	SPS
SAP Mount Directory	/sapmnt
Password for All Users	<SAP User Password>
Password of SAP System Administrator	<SAP Admin Password>
User ID	Leave empty
Group ID of sapsys	Leave empty
Specify path to SAPEXE.SAR	/sap-install
Specify path to SAPHOSTAGENT.SAR	/sap-install
ASCS Instance Number	10
ASCS Instance Host Name	sps-ascs
ABAP Message Server Port	3610
Internal ABAP Message Server Port	3910
Yes, clean up operating system users	Click

6. Review the parameters and proceed with the installation.

*Note: If the installation fails due to insufficient permissions on the SAP file systems, modify the permissions as described in the next section (Modify SAP File System Permissions) and retry the installation.

7. Execute the following command on node-a to clean up SAP installation files:

[root@node-a ~]# rm -rf /root/.sapinst

Modify SAP File System Permissions

Execute the following commands on node-a to set the correct permissions on the SAP file systems:

[root@node-a ~]# chown -R spsadm /sapnfs/usr/sap/SPS /sapmnt/SPS /usr/sap/SPS
[root@node-a ~]# chgrp -R sapsys /sapnfs /sapmnt /usr/sap

Install the ERS Instance

Complete the following steps to install the ERS20 instance on node-b.

1. If installing from a remote system, add a firewall rule to allow inbound traffic on TCP port 4237 (the port which exposes the sapinst graphical interface) on node-b.

2. Execute the following command on node-b to initiate sapinst with the virtual hostname associated to the ERS instance:

[root@node-b ~]# /sap-install/sapinst SAPINST_USE_HOSTNAME=sps-ers

*Note: The SAPINST_REMOTE_ACCESS_USER=<user> parameter may be used to allow login to the sapinst graphical interface by a non-root user.

*Note: If sapinst displays an error due to a missing dt_socket transport library, install the libnsl package with yum install -y libnsl.

3. To access the sapinst graphical interface, use a web browser to navigate to https://<node-b Public IP>:4237/sapinst/docs/index.html.

4. Select Software Provisioning Manager 2.0 SP XX → SAP S/4HANA Server 1909 → SAP HANA Database → Installation → Application Server ABAP → High-Availability System → ERS Instance and click Next.

5. Provide the following parameters when installing the ERS instance. The icon indicates that the default option is chosen.

Field	Value
Profile Directory	/sapmnt/SPS/profile
Password of SAP System Administrator (spsadm)	<spsadm User Password>
Specify path to SAPHOSTAGENT.SAR	/sap-install
Password of SAP System Administrator (sapadm)	<spsadm User Password>
User ID	Leave empty
Group ID of sapsys	Use default value
Name of the ASCS Instance to be Replicated	ASCS10
Number of the ASCS Instance to be Replicated	10
Number of the ERS Instance	20
ERS Instance Host	sps-ers
Yes, clean up operating system users	Click

6. Review the parameters and proceed with the installation.

*Note: If the installation fails due to insufficient permissions on the SAP file systems, modify the permissions as described in the Modify SAP File System Permissions section and retry the installation.

7. Execute the following command on node-b to clean up SAP installation files:

[root@node-b ~]# rm -rf /root/.sapinst

Modify /usr/sap/sapservices on Both Nodes

Since we only installed the ASCS10 instance on node-a and only installed the ERS20 instance on node-b, the /usr/sap/sapservices file is incomplete on each node. Modify this file on both node-a and node-b so that it contains entries for both the ASCS10 and ERS20 instances.

# vi /usr/sap/sapservices
# cat /usr/sap/sapservices
#!/bin/sh
LD_LIBRARY_PATH=/usr/sap/SPS/ASCS10/exe:$LD_LIBRARY_PATH; export LD_LIBRARY_PATH; /usr/sap/SPS/ASCS10/exe/sapstartsrv pf=/usr/sap/SPS/SYS/profile/SPS_ASCS10_sps-ascs -D -u spsadm
LD_LIBRARY_PATH=/usr/sap/SPS/ERS20/exe:$LD_LIBRARY_PATH; export LD_LIBRARY_PATH; /usr/sap/SPS/ERS20/exe/sapstartsrv pf=/usr/sap/SPS/SYS/profile/SPS_ERS20_sps-ers -D -u spsadm

Restart the ASCS Instance to Enable Enqueue Replication

Now that the ERS instance has been installed on node-b, the ASCS instance and its corresponding SAP Start Service process must be restarted on node-a in order to enable enqueue replication. Execute the following commands on node-a to restart the ASCS instance and verify that enqueue replication has been enabled.

1. [root@node-a ~]# su - spsadm -c “sapcontrol -nr 10 -function RestartService SPS”
   15.03.2021 00:29:23
   RestartService
   OK

2. [root@node-a ~]# su - spsadm -c “sapcontrol -nr 10 -function StopWait 60 2”
   15.03.2021 00:29:44
   Stop
   OK

3. [root@node-a ~]# su - spsadm -c “sapcontrol -nr 10 -function StartWait 60 2”
   15.03.2021 00:30:07
   Start
   OK

4. [root@node-a ~]# su - spsadm -c “sapcontrol -nr 10 -function EnqGetStatistic | grep replication_state”
   replication_state: GREEN

Modify /etc/default/LifeKeeper on Both Nodes

Add the following entries to /etc/default/LifeKeeper on both node-a and node-b:

NFS_RPC_PROTOCOL=tcp
SAP_NFS_CHECK_DIRS=/sapnfs

The SAP_NFS_CHECK_DIRS entry allows LifeKeeper to check the availability of the Cloud Volume mount target exporting the cv-sapnfs NFS share before performing SAP-related operations, and the NFS_RPC_PROTOCOL entry tells LifeKeeper to use the TCP protocol when checking availability of the NFS server.

Verify Successful ASCS and ERS Installation

Execute the following commands to verify that the ASCS10 and ERS20 instances are running successfully on node-a and node-b, respectively.

1. [root@node-a ~]# su - spsadm -c "sapcontrol -nr 10 -function GetProcessList"
   01.01.2021 00:00:00
   GetProcessList
   OK
   name, description, dispstatus, textstatus, starttime, elapsedtime, pid
   msg_server, MessageServer, GREEN, Running, 2021 01 01 00:00:00, 0:00:00, 8420
   enq_server, Enqueue Server 2, GREEN, Running, 2021 01 01 00:00:00, 0:00:00, 8428

2. [root@node-b ~]# su - spsadm -c "sapcontrol -nr 20 -function GetProcessList"
   01.01.2021 00:00:00
   GetProcessList
   OK
   name, description, dispstatus, textstatus, starttime, elapsedtime, pid
   enq_replicator, Enqueue Replicator 2, GREEN, Running, 2021 01 01 00:00:00, 0:00:00, 25263

Install PAS and AAS Instances

Once the database (e.g., SAP HANA) has been installed and configured for high-availability, use SWPM 2.0 to install one Primary Application Server (PAS) and one Additional Application Server (AAS) instance on two external application server nodes spread across two availability zones. As application server redundancy is provided by the existence of the AAS instance, the application server instances do not require LifeKeeper protection. Note that the previously created NFS shares containing the /sapmnt/SPS and /usr/sap/trans file systems must be mounted on both the PAS and AAS instance hosts before installation. Please consult SAP documentation for details on the installation of the PAS and AAS instances.

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