Home > Workload Solutions > SAP > Guides > SAP HANA TDI Guides > Dell Validated Solution for SAP HANA TDI Deployments with Dell Unity XT Storage > Host connection using FC SAN
When you connect an SAP HANA host to a Unity XT storage array using the FC protocol, you must connect two HBA ports supporting 16/32 Gb/s link speed to the array. Dell Technologies recommends using two redundant HBAs for HA, but you can use a single dual-port HBA instead.
Connect and zone each port over the FC SAN network to two FC FE ports per storage processor on the Unity XT array. This configuration produces two active and two standby paths per LUN, as shown in the following figure:
Figure 5. Redundant Fibre Channel host connection
After the HBAs have been zoned to the Unity XT FC front-end ports, use the Unisphere UI to create a host entry in the Unity XT system and add LUNs to the host.
The Add a Host page is displayed:
Figure 6. Adding a host using Unisphere
The Properties page is displayed:
Figure 7. Unisphere host properties: FC initiators
You can now create LUNs and add them to the host.
To scan the new LUNs on the SAP HANA host, run the following command:
rescan-scsi-bus.sh
After the new LUNs have been rescanned and are visible to the host, add them to multipathing (DM-MPIO). Native Linux multipathing (DM-MPIO) must be enabled on the Linux host. When multipathing is enabled, the host accesses the block LUNs over multiple paths, which provides redundancy if there is a component failure.
Multipathing is controlled by the /etc/multipath.conf file. The file does not exist by default. Create the file by running the following command:
multipath -t > /etc/multipath.conf
The Unity XT devices are controlled under the ^DGC device section. All default settings work for FC devices; however, it might be necessary to change some of the settings based on specific requirements, for example to exclude some block devices such as the internal server devices from multipathing.
After the block devices are under multipath control, run:
multipath -ll
The following sample output shows two devices:
3600601604f804a00fc8a775d7498625e dm-12 DGC,VRAID
size=512G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio=50 status=active
| |- 24:0:0:11 sdba 67:64 active ready running
| `- 29:0:0:11 sdek 128:192 active ready running
`-+- policy='service-time 0' prio=10 status=enabled
|- 22:0:0:11 sdal 66:80 active ready running
`- 27:0:0:11 sddm 71:64 active ready running
3600601604f804a00079d565d880a5877 dm-2 DGC,VRAID
size=768G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio=50 status=active
| |- 1:0:0:1 sdo 8:224 active ready running
| `- 20:0:0:1 sdy 65:128 active ready running
`-+- policy='service-time 0' prio=10 status=enabled
|- 1:0:1:1 sdt 65:48 active ready running
`- 20:0:1:1 sdad 65:208 active ready running
When the block devices are under multipath control, you can format them by using XFS and mount them as required.
To format the block device, run the following (sample) command:
mkfs.xfs /dev/mapper/3600601604f804a00fc8a775d7498625e
When installing an SAP HANA single-node instance, automate the mounting of the SAP HANA persistent devices by running /etc/fstab. For example:
/dev/mapper/3600601604f804a00079d565d880a5877 /hana/data xfs rw,relatime,noquota 0 0
/dev/mapper/3600601604f804a00fc8a775d7498625e /hana/log xfs rw,relatime,noquota 0 0
When you install an SAP HANA multimode scale-out cluster, the SAP HANA storage connector (fcClient) mounts the devices during SAP HANA startup.