Each SAP HANA host requires a network connection with 25 Gb/s link speed to the dedicated storage network switches. For redundancy, the connection must have at least two NICs.
With two 25 Gb/s NICs on the SAP HANA hosts, you can optionally configure active/active interface groups on the SAP HANA hosts to use network bonding (bonds), where multiple network interfaces are aggregated into a single logical bonded interface. Hosts that are configured with bonds require MLAG and LACP on the switches. The following figure shows a sample network topology for eight SAP HANA nodes with two
25 Gb/s NICs, each connected through redundant switches to all four 25 Gb/s IP interface ports on the PowerStore system:
The file systems for the SAP HANA persistence are created on the PowerStore appliance, as described in Creating NAS file systems for the SAP HANA persistence. Add the _netdev mount option when mounting NAS devices. This mount option prevents the system from attempting to mount these file systems until the network has been enabled on the system.
When you install an SAP HANA system, either as a single-node instance or a multimode scale-out cluster, you must automate the mounting of the SAP HANA persistent devices by using /etc/fstab. The mounts must be evenly distributed across the PowerStore IP address of the NAS servers on both PowerStore nodes within the appliance.
This section is applicable for both FC SAN and NAS/NFS deployments. The SAP HANA shared file system is used for the SAP HANA binary, trace, and some configuration files. The shared file system must be mounted under the /hana/shared mount point. In SAP HANA single node (scale-up) systems, the file system can reside on a block volume using the XFS file system. For SAP HANA scale-out systems, this file system must be shared across all scale-out nodes, including worker and standby nodes.
Note: The /hana/shared file system must be shared on all hosts on SAP HANA scale-out systems in both FC SAN and NAS/NFS deployments.
To create a NAS/NFS shared file system on a PowerStore system, follow these steps in the PowerStore Manager UI. If NAS servers already exist in the UI, skip these steps.
The following page opens:
To create an SAP HANA shared file system:
The Create File System page opens, as shown in the following figure:
The Create a File System Details page opens, as shown in the following figure:
On the SAP HANA host:
mkdir -p /hana/shared
<NAS Server>:/hanashared /hana/shared nfs4 rw,bg,hard,timeo=600,intr,noatime,vers=4.0,rsize=1048576,wsize=1048576,lock,_netdev 0 0
where <NAS Server> is the IP address or hostname of your NAS server on the PowerStore system.
If you are using NFSv3, adjust the NFS version.
When creating file systems for the SAP HANA persistence, follow these configuration guidelines:
This step is important for performance and load-balancing. For example, place data and log for the first SAP HANA node on NAS server A and place data and log for the second SAP HANA node on NAS server B. Continue to balance subsequent nodes across the two NAS servers. The following figure shows an example:
On the SAP HANA hosts, create the mount points by running the following commands, where x = 1, 2, 3, and so on up to the number of hosts in the scale-out system:
mkdir -p /hana/data/SID/mnt0000x
mkdir -p /hana/data/SID/mnt0000x
chmod -R 777 /hana/data/SID/
chmod -R 777 /hana/log/SID/
Note: For SAP HANA scale-out systems, all the mount points must be created on each host.
Add the entries to /etc/fstab:
<NAS Server>:/<filesystem> /hana/shared nfs4 rw,bg,hard,timeo=600,intr,noatime,vers=4.0,rsize=1048576,wsize=1048576,lock,_netdev 0 0
where <NAS Server> is the IP address or hostname of your NAS server on the PowerStore system. If you are using NFSv3, adjust the NFS version.
To achieve optimal performance, ensure that the SAP HANA mounts are evenly distributed across all available PowerStore front-end IP networks of the NAS servers in the /etc/fstab file. For more information, see Host connection and setup using NAS/NFS.
In a 2+1 SAP HANA scale-out system with SID = NAS, the mount points are included in the /etc/fstab file on each of the SAP HANA clients including any standby hosts. The following code extract shows an example:
If preferred, use the following example for /etc/fstab with NFSv3 parameters.
The operating system command mount –a mounts all the directories from the PowerStore system. Run this command on each SAP HANA client.