Minimum RAM for HANA to install BW 7.3 Ehp1

[Private_Member_88512]

Hi

I'm installing BW 7.3 Ehp1 with HANA DB and the sapinst get stop because run out of memory (mentioned clearly in the log) during ABAP import phase.

This server is for BW developement so the physical memory that we have is 12 GB and it seems like not enough.

If that so, then what is the minimum RAM should I install into the HANA server? 32 GB ? 64 GB? or 1 TB of ram in order to run the BW on top of the HANA?

note: We won't spend too much ram for a DEV system.

Thanks,

Halomoan

[lbreddemann]

HI Halomoan,

the RAM size required to install and setup a BW on HANA system needs to be determined by the sizing tool (based on the sizing script or ABAP report).

As the minimum HANA building block is 64MB going below that simply leads to a non-supported platform that might or might not work properly.

If you use less memory than determined by your sizing process, then what you would typically find is that the performance is far worse (factors of scale worse).

While you might argue that this is just a development system for which you would accept bad performance, this would also mean that you have no way to detect possible performance issues before running your queries in the properly sized production system.

Thus, it's not only not supported, it also brings severe limitations in what you can do with your DEV environment.

Cheers,

Lars

[Private_Member_88512]

Hi Lars

I agree with you.

It would become a very expensive DEV system in our SAP history.

Now i look into the SAP Notes for HANA sizing, all of them describe only how to do sizing for BW migration with the sizing script or the ABAP report. In our case, we are about to do a fresh install with ABAP export which downloaded from the SAP software download website.

Then how to determine what is the minimum RAM?

Regards,

Halomoan

[lbreddemann]

In that case the quick sizer tool is the way to go.

Just as you would do with any other fresh SAP installation.

[Private_Member_88512]

Thanks. I'll look into the sizing tool. At glance, I see +94 GB ram.

[Derek_Fox]

Hi

Based on our experiements in our LAB regarding the HANA Standalone scenario and our proof of concept BW on HANA migration, going for the minimum amount of memory means that the performance of the BW on HANA development system you are trying to build will be severly hampered. As Lars has mention above, 64Gb is the minimum, however this is not enough to run a BW on HANA system.

Unfortunately one of the issues with calculating the memory required is the future requirements and demands placed on the BW on HANA system at some time in the future. The Quick Sizer tool can provide an initial estimate but this is based on the values entered (subjective/approximations).

When determining the memory requirements, one uses the Quick sizer to have a number but you must complement it with some manually calculations based on certain parameters and scenarios, this will the provide a low, a high and a mid-point number from which you can evaluate the size of the memory required.

If I use my BW development system prior to a BW on HANA migration as a basis to determine the memory required, you are looking at between 192Gb to 256GB memory as a minimum.

Regards

Derek

[Private_Member_88512]

Hi Derek

If I spend 64 GB or 256 GB for my BW master data and transaction it's fine and I'm ok with it.

But the BW misc tables like ABAP program tables, temp tables, statistic tables are stored in the HANA memory too and that the reason why for a fresh BW installation on HANA already requires > 64 GB of RAM !  I believe all the tables are a Row type table where they will be loaded into the RAM on startup.

For me, that is a waste.

Halomoan