SAP HANA (Large Instances) storage architecture

In this article, we'll look at the storage architecture for deploying SAP HANA on Azure Large Instances (also known as BareMetal Infrastructure).

The storage layout for SAP HANA on Azure (Large Instances) is configured by SAP HANA on the classic deployment model per SAP recommended guidelines. For more information on the guidelines, see SAP HANA storage requirements.

Type I class of HANA Large Instances come with four times the memory volume as storage volume. Whereas Type II class of HANA Large Instances come with a volume intended for storing HANA transaction log backups. For more information, see Install and configure SAP HANA (Large Instances) on Azure.

See the following table for storage allocation. The table lists the rough capacity for volumes provided with the different HANA Large Instance units.

HANA Large Instance SKU hana/data hana/log hana/shared hana/logbackups
S72 1,280 GB 512 GB 768 GB 512 GB
S72m 3,328 GB 768 GB 1,280 GB 768 GB
S96 1,280 GB 512 GB 768 GB 512 GB
S192 4,608 GB 1,024 GB 1,536 GB 1,024 GB
S192m 11,520 GB 1,536 GB 1,792 GB 1,536 GB
S192xm 11,520 GB 1,536 GB 1,792 GB 1,536 GB
S384 11,520 GB 1,536 GB 1,792 GB 1,536 GB
S384m 12,000 GB 2,050 GB 2,050 GB 2,040 GB
S384xm 16,000 GB 2,050 GB 2,050 GB 2,040 GB
S384xxm 20,000 GB 3,100 GB 2,050 GB 3,100 GB
S576m 20,000 GB 3,100 GB 2,050 GB 3,100 GB
S576xm 31,744 GB 4,096 GB 2,048 GB 4,096 GB
S768m 28,000 GB 3,100 GB 2,050 GB 3,100 GB
S768xm 40,960 GB 6,144 GB 4,096 GB 6,144 GB
S960m 36,000 GB 4,100 GB 2,050 GB 4,100 GB
S896m 33,792 GB 512 GB 1,024 GB 512 GB

More recent SKUs of HANA Large Instances are delivered with the following storage configurations.

HANA Large Instance SKU hana/data hana/log hana/shared hana/logbackups
S224 4,224 GB 512 GB 1,024 GB 512 GB
S224oo 6,336 GB 512 GB 1,024 GB 512 GB
S224m 8,448 GB 512 GB 1,024 GB 512 GB
S224om 8,448 GB 512 GB 1,024 GB 512 GB
S224ooo 10,560 GB 512 GB 1,024 GB 512 GB
S224oom 12,672 GB 512 GB 1,024 GB 512 GB
S448 8,448 GB 512 GB 1,024 GB 512 GB
S448oo 12,672 GB 512 GB 1,024 GB 512 GB
S448m 16,896 GB 512 GB 1,024 GB 512 GB
S448om 16,896 GB 512 GB 1,024 GB 512 GB
S448ooo 21,120 GB 512 GB 1,024 GB 512 GB
S448oom 25,344 GB 512 GB 1,024 GB 512 GB
S672 12,672 GB 512 GB 1,024 GB 512 GB
S672oo 19,008 GB 512 GB 1,024 GB 512 GB
S672m 25,344 GB 512 GB 1,024 GB 512 GB
S672om 25,344 GB 512 GB 1,024 GB 512 GB
S672ooo 31,680 GB 512 GB 1,024 GB 512 GB
S672oom 38,016 GB 512 GB 1,024 GB 512 GB
S896 16,896 GB 512 GB 1,024 GB 512 GB
S896oo 25,344 GB 512 GB 1,024 GB 512 GB
S896om 33,792 GB 512 GB 1,024 GB 512 GB
S896ooo 42,240 GB 512 GB 1,024 GB 512 GB
S896oom 50,688 GB 512 GB 1,024 GB 512 GB

Actual deployed volumes might vary based on deployment and the tool used to show the volume sizes.

If you subdivide a HANA Large Instance SKU, a few examples of possible division pieces might look like:

Memory partition in GB hana/data hana/log hana/shared hana/log/backup
256 400 GB 160 GB 304 GB 160 GB
512 768 GB 384 GB 512 GB 384 GB
768 1,280 GB 512 GB 768 GB 512 GB
1,024 1,792 GB 640 GB 1,024 GB 640 GB
1,536 3,328 GB 768 GB 1,280 GB 768 GB

These sizes are rough volume numbers that can vary slightly based on deployment and the tools used to look at the volumes. There are also other partition sizes, such as 2.5 TB. These storage sizes are calculated using a formula similar to the one used for the previous partitions. The term "partitions" doesn't mean the operating system, memory, or CPU resources are partitioned. It indicates storage partitions for the different HANA instances you might want to deploy on one single HANA Large Instance unit.

If you need more storage, you can buy more in 1-TB units. The extra storage may be added as more volume or used to extend one or more of the existing volumes. You can't reduce the sizes of the volumes as originally deployed and as documented by the previous tables. You also aren't able to change the names of the volumes or mount names. The storage volumes previously described are attached to the HANA Large Instance units as NFS4 volumes.

You can use storage snapshots for backup and restore and disaster recovery purposes. For more information, see SAP HANA (Large Instances) high availability and disaster recovery on Azure.

For more information on the storage layout for your scenario, see HLI supported scenarios.

Run multiple SAP HANA instances on one HANA Large Instance unit

It's possible to host more than one active SAP HANA instance on HANA Large Instance units. To provide the capabilities of storage snapshots and disaster recovery, such a configuration requires a volume set per instance. Currently, HANA Large Instance units can be subdivided as follows:

  • S72, S72m, S96, S144, S192: In increments of 256 GB, with 256 GB as the smallest starting unit. Different increments such as 256 GB and 512 GB can be combined to the maximum memory of the unit.
  • S144m and S192m: In increments of 256 GB, with 512 GB as the smallest unit. Different increments such as 512 GB and 768 GB can be combined to the maximum memory of the unit.
  • Type II class: In increments of 512 GB, with the smallest starting unit of 2 TB. Different increments such as 512 GB, 1 TB, and 1.5 TB can be combined to the maximum memory of the unit.

The following examples show what it might look like running multiple SAP HANA instances.

SKU Memory size Storage size Sizes with multiple databases
S72 768 GB 3 TB 1x768-GB HANA instance
or 1x512-GB instance + 1x256-GB instance
or 3x256-GB instances
S72m 1.5 TB 6 TB 3x512GB HANA instances
or 1x512-GB instance + 1x1-TB instance
or 6x256-GB instances
or 1x1.5-TB instance
S192m 4 TB 16 TB 8x512-GB instances
or 4x1-TB instances
or 4x512-GB instances + 2x1-TB instances
or 4x768-GB instances + 2x512-GB instances
or 1x4-TB instance
S384xm 8 TB 22 TB 4x2-TB instances
or 2x4-TB instances
or 2x3-TB instances + 1x2-TB instances
or 2x2.5-TB instances + 1x3-TB instances
or 1x8-TB instance

There are other variations as well.

Encryption of data at rest

The storage for HANA Large Instances uses transparent encryption for the data, as it's stored on the disks. In deployments before the end of 2018, you could have the volumes encrypted. If you decided against that option, you could have the volumes encrypted online. The move from non-encrypted to encrypted volumes is transparent and doesn't require downtime.

With the Type I class of SKUs of HANA Large Instance, the volume storing the boot LUN is encrypted. In Revision 3 HANA Large Instance stamps using Type II class of SKUs, you need to encrypt the boot LUN with OS methods. In Revision 4 HANA Large Instance stamps using Type II class of SKUs, the volume storing the boot LUN is encrypted at rest by default.

Required settings for larger HANA instances on HANA Large Instances

The storage used in HANA Large Instances has a file size limitation. The size limitation is 16 TB per file. Unlike file size limitations in the EXT3 file systems, HANA isn't implicitly aware of the storage limitation enforced by HANA Large Instances storage. As a result, HANA won't automatically create a new data file when the file size limit of 16 TB is reached. As HANA attempts to grow the file beyond 16 TB, HANA will report errors and the index server will finally crash.

Important

In order to prevent HANA from trying to grow data files beyond the 16 TB file size limit of HANA Large Instance storage, you need to set the following parameters in the global.ini configuration file of HANA:

  • datavolume_striping=true
  • datavolume_striping_size_gb = 15000
  • See also SAP note #2400005
  • Be aware of SAP note #2631285

Next steps

Learn about deploying SAP HANA (Large Instances).