SAP HANA Implementation and Best Practices

Operating System Settings

cat /sys/block/sda/queue/scheduler
[none] mq-deadline kyber bf

ACTION=="add|change", KERNEL=="sd*[!0-9]", SUBSYSTEM=="block", ENV{ID_VENDOR}=="PURE", ATTR{queue/scheduler}="none"
ACTION=="add|change", KERNEL=="dm*[!0-9]", SUBSYSTEM=="block", ENV{ID_VENDOR}=="PURE", ATTR{queue/scheduler}="none"

File System Settings

The recommended file system to use with FlashArray Block devices is the XFS file system for both data and log volumes.

When creating and mounting each respective file system, use the default mount options for both the log and data volume formatted with the XFS filesystem.

SAP HANA Scale Up on FlashArray

Scale up deployments focus on single resource domain in terms of computational power. Scale of the system is achieved by increasing the existing CPU power or adding more memory to a single server. This is the simplest and highest performing type of installation.

Scale up deployments can be converted to Scale Out by adding additional servers to the landscape.

The following volumes and size recommendations are created and mounted before installation:

SAP HANA Scale Out on FlashArray

Scale out deployments offer superior scale and additional high availability options in comparison to Scale Up deployments. Multiple nodes or servers are combined into a single system.  Scale out systems allow for each host to be given a specific role:

Within this guide, only worker and standby hosts are used. Additional hosts can be added with other roles. 

The following volumes and size recommendations are created before installation:

SAP HANA Scale Out installation

When installing or expanding an SAP HANA system to be a scale out (distributed) system some configuration considerations need to be taken into account.

In the event of a host failure in a distributed system, a standby host will take over the persistence of the failing host. This is done through the use of the SAP HANA Storage Connector API. 

In order for an SAP HANA scale out system to be installed the global.ini file must first be configured:

1. Identify the WWIDN of the block storage devices to be used for data and log volumes. this can be found using the commands "multipath -ll", "lsblk" or "udevadm --query=all --name {device name} | grep | DM_NAME.
2. Create or add(depending on the scenario) the following lines to the global.ini file(The below assumes a 2 + 1 configuration, with 2 worker nodes and one standby node):

[persistence]
basepath_datavolumes={data volume path - typically /hana/data/<SID>}
basepath_logvolumes={log volume path - typically /hana/log/<SID>}
use_mountpoints=yes
basepath_shared=yes
[storage]
ha_provider=hdb_ha.fcClient
partition_*_*__prtype=5
partition_1_data__wwid={wwid of data volume}
partition_1_log__wwid={wwid of log volume}
partition_2_data__wwid={wwid of data volume}
partition_2_log__wwid={wwid of log volume}

Note the use of "partition_*_*__prtype=5" this informs the storage API connector that the reservation type to use for each volume is Write Exclusive.

3. Ensure that all of the volumes to be used for log and data can be seen but not mounted by each host in the SAP HANA scale out landscape.
4. To perform the installation from the command line, as the root user pass in the location of the global.ini file (this is assuming a new system installation):

./hdblcm --storage_cfg={path to global.ini}

For any more information on the SAP HANA Storage API connector, please see SAP Note 1922823.

Shared filesystem for Scale Out SAP HANA

SAP HANA distributed (scale out) deployments required a shared filesystem exported to each node in the landscape for the installation to succeed.

Any generic NFS provider supporting NFS v3 and above can be used.

When using Purity 6.4.2 and later FlashArray File Services can be used to provide a shared filesystem (NFS) for Scale Out SAP HANA deployments.