File Services - NFS

The following configurations need to be performed on the relevant FlashArray to ensure a successful SAP HANA installation :

Networking

Ensure that at least one virtual interface (vif) with the file service is configured and enabled. It should be reachable from each of the SAP HANA nodes.

The networking configuration can be seen under Settings -> Network In the FlashArray graphical user interface.

File systems, directories and policies

• One file system should be created per instance.
• A single /hana/shared directory should be created within that file system. Do not use the default, root directory.
• A /hana/data and /hana/log directory should be created per node in the instance.
  • The below image showcases an example of how a multi-host deployment would be configured.
  • Example : For a 3+1 scale out configuration the following managed directories need to be created within the same file system
    • 3 directories for HANA-Data
    • 3 directories for HANA-Log
    • 4 directories for /usr/sap/<SID>
    • 1 directory for HANA-Shared
• A policy should be created per instance and then attached to each directory.
  • Rules should include the following :
    • Clients - Only the SAP HANA nodes should be added as clients
    • Access- no-root-squash
    • permission rw
    • Version - NFSv3 or NFSv4 depending on requirements
  • Details should include the following:
    • Type - NFS
    • Enabled - true
    • User Mapping Enabled - false (Disabling NFS User Mapping)
    • Version - NFSv3 or NFSv4 depending on requirements

The below image is an example of a policy configuration for a scale up instance :

(Host) Operating System Configuration

SUSE Linux Enterprise

To optimize the deployment of SAP HANA on SUSE 12, or 15 kernel parameters need be to be manually set when not using saptune (see the SAP Note 3024356). This can be done by creating a file in the /etc/sysctl.d directory name 91-Pure-NFS-HANA.conf with the following contents :

net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 131072 16777216
net.ipv4.tcp_wmem = 4096 16384 16777216
net.core.netdev_max_backlog = 300000
net.ipv4.tcp_slow_start_after_idle=0
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_moderate_rcvbuf = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_sack = 1

The parameter, sunrpc.tcp_max_slot_table_entries, needs to be set in /etc/modprobe.d/sunrpc.conf with the following line addition :

options sunrpc tcp_max_slot_table_entries=128

Red Hat Enterprise Linux

To optimize the deployment of SAP HANA on SUSE 12, or 15 kernel parameters need be to be manually set (for the use of the RHEL System Roles for SAP see the SAP Note 3024356). This can be done by creating a file in the /etc/sysctl.d directory name 91-Pure-NFS-HANA.conf with the following contents :

net.core.rmem_max = 16777216
net.core.wmem_max = 16777216
net.ipv4.tcp_rmem = 4096 131072 16777216
net.ipv4.tcp_wmem = 4096 16384  16777216
net.core.netdev_max_backlog = 300000
net.ipv4.tcp_slow_start_after_idle=0
net.ipv4.tcp_no_metrics_save = 1
net.ipv4.tcp_moderate_rcvbuf = 1
net.ipv4.tcp_window_scaling = 1
net.ipv4.tcp_timestamps = 1
net.ipv4.tcp_sack = 1

The parameter, sunrpc.tcp_max_slot_table_entries, needs to be set in /etc/modprobe.d/sunrpc.conf with the following line addition :

options sunrpc tcp_max_slot_table_entries=128

Supported Configurations for RHEL and SUSE Enterprise Linux

The following table sets out the supported configurations for SAP HANA deployments with FlashArray file services

Mount Options

The following mount options are recommended for use with FlashArray file services- NFS :

<vif>:/<Export-name>   /mountpoint      nfs     rsize=1048576,wsize=1048576,nconnect=8,hard,mountproto=tcp      0  0