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
# chmod 600 /swap/swapfile.img
# mkswap /swap/swapfile.img
# echo "/swap/swapfile.img    swap    swap    sw    0 0" >> /etc/fstab
# swapon /swap/swapfile.img
  1. 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
  1. On node-a and node-b, create a /sap-install directory which will contain the SAP installation files.
# mkdir /sap-install
  1. 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
  1. Use SAPCAR to extract the files for SWPM 2.0.
# cd /sap-install
# ./SAPCAR -xvf SWPM20SPxx_x-xxxx.SAR

Before installing the SAP instances, verify that all shared and replicated file systems described in the appropriate cloud-specific subsection of Create SAP File Systems are mounted correctly on node-a and/or 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.

If deploying on AWS or Microsoft Azure, the LifeKeeper GUI should resemble the following image:

If deploying on Google Cloud, the LifeKeeper GUI should resemble the following image:

Install the ASCS Instance on Node-A

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.
  1. 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
  1. To access the sapinst graphical interface, use a web browser to navigate to https://<node-a Public IP>:4237/sapinst/docs/index.html.
  1. 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.

  1. 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
  1. Review the parameters and proceed with the installation.
  1. Execute the following command on node-a to clean up SAP installation files:
[root@node-a ~]# rm -rf /root/.sapinst

Prepare Node-B For ERS Instance Installation

Complete the following steps to prepare node-b for installation of the ERS instance. In particular, this step will create the necessary users and groups, install SAP Host Agent, and install required binaries into the /usr/sap/SPS/SYS directory 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.
  1. Execute the following command on node-b to initiate sapinst:
[root@node-b ~]# /sap-install/sapinst
  1. To access the sapinst graphical interface, use a web browser to navigate to https://<node-b Public IP>:4237/sapinst/docs/index.html.
  1. Select Software Provisioning Manager 2.0 SP XX → SAP S/4HANA Server 1909 → SAP HANA Database → Installation → Application Server ABAP → High-Availability System → Prepare Additional Cluster Node and click Next.

  1. Provide the following parameters when preparing node-b for installation of the ERS instance.
Field
Value
Profile Directory /sapmnt/SPS/profile
Password of SAP System Administrator <SAP Admin Password>
Specify path to SAPHOSTAGENT.SAR /sap-install
Yes, clean up operating system users Click
  1. Review the parameters and proceed with the installation.
  1. Execute the following command on node-b to clean up SAP installation files:
[root@node-b ~]# rm -rf /root/.sapinst

Modify SAP File System Permissions

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

# chown -R spsadm /export/sapmnt/SPS /sapmnt/SPS /usr/sap/SPS
# chgrp -R sapsys /export/{usr/sap,sapmnt} /sapmnt /usr/sap

Install the ERS Instance on Node-B

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.
  1. 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
  1. To access the sapinst graphical interface, use a web browser to navigate to https://<node-b Public IP>:4237/sapinst/docs/index.html.
  1. 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.

  1. 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
  1. Review the parameters and proceed with the installation.
  1. 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.

  1. Verify that the following lines appear in the default profile for the LifeKeeper SAP installation (/usr/sap/SPS/SYS/profile/DEFAULT.PFL). If they do not exist, add them.
enq/replicatorhost = sps-ers
enq/replicatorinst = 20
  1. Execute the following commands on node-a to restart the ASCS instance and verify that enqueue replication has been enabled.
[root@node-a ~]# su - spsadm -c "sapcontrol -nr 10 -function StopWait 60 2"
15.03.2021 00:29:23
Stop
OK
[root@node-a ~]# su - spsadm -c "sapcontrol -nr 10 -function RestartService SPS"
15.03.2021 00:29:44
RestartService
OK
[root@node-a ~]# su - spsadm -c "sapcontrol -nr 10 -function StartWait 60 2"
15.03.2021 00:30:07
Start
OK
[root@node-a ~]# su - spsadm -c "sapcontrol -nr 10 -function EnqGetStatistic | grep replication_state"
replication_state: GREEN

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
  1. [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 for 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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