Simpler Navigation for Servers and Operating Systems - Please Update Your Bookmarks
Completed: a much simpler Servers and Operating Systems section of the Community. We combined many of the older boards, so you won't have to click through so many levels to get at the information you need. Check the consolidated boards here as many sub-forums are now single boards.
If you have bookmarked forums or discussion boards in Servers and Operating Systems, we suggest you check and update them as needed.
Operating System - VMware
Showing results for 
Search instead for 
Did you mean: 

VS4 NUMA nodes imbalance

Go to solution
Regular Advisor

VS4 NUMA nodes imbalance

Hi Folks,

Recently we've found this message after a successful ESX4 installation:

"Signficant imbalance between NUMA nodes detected. Performance may be impacted."

Server is a BL460c G6, with two CPUs and a dissimilar amount of ram (3x2GB and 1x4GB).

Is there a way to disable NUMA funcionality within the RBSU or boot-time parameters?

Thanks a lot for your responses,

Uwe Zessin
Honored Contributor

Re: VS4 NUMA nodes imbalance

From my understanding, NO, because the memory controller is embedded in the CPU - there is no shared memory bus: if processor A wants data from memory that is connected to processor B it uses the 'QuickPath Interconnect' between proc A+B. B fetches the data from its local memory and sends it across the QPI to A.
Daniel Bowers
Trusted Contributor

Re: VS4 NUMA nodes imbalance

You can disable NUMA within RBSU on the BL460c G6 by setting "Enable Node Interleaving" within the "Advanced Options / Advanced Performance Tuning Options" menu to "Enable".

This will cause the BIOS to alternate between the two processors' memory when building the system memory map.

I'm not sure how VS4 will perform, though.
Regular Advisor

Re: VS4 NUMA nodes imbalance

hi experts
does the g6 line if blade system use NUMA or advanced ecc for memory configuration?
Regular Advisor

Re: VS4 NUMA nodes imbalance

Hi ilayy,

NUMA (Non-Uniform Memory Access) is a technique to address and use memory distributed in different processors/memory controllers within the same physical system.

ECC (eror checking and correcting) allows the memory subsystem to detect memory errors and instruct the system to either correct the error or halt the system to prevent data loss/corruption (advanced ECC in the 460c G6)

The BL460c G6 supports both technologies.

Hope it helps,
Occasional Advisor

Re: VS4 NUMA nodes imbalance

Hello Guys,

Seems like you looked for this article:

Note: If one of the physical RAM modules is damaged or faulty, it will also cause an imbalance and thus causing the error to be thrown in the ESX console.

bl460 g6 is non-NUMA, I guess and the imbalance is caused by failing DIMM or DIMMs.

No RISC, no fun!

Re: VS4 NUMA nodes imbalance

Hi There,

As per g6 memory rules, you can install different size memory accross processor but when it comes to ESX 4 it looks for similar memory configuration for both the processors and you will get this message...

disabling it from RBSU is one option and getting the patch from vmware for this issue is a permanent solution.


I work for HP
Looking for a quick resolution to a technical issue for your HP Enterprise products? HP Support Center Knowledge-base – Just a Click Away!
See Self Help Post for more details