Heap size VMFS3

http://www.yellow-bricks.com has a blog titled : Heap size VMFS3


Posted by Duncan Epping in December 19th, 2008

I was talking to a fellow consultant today. He ran into the following error messages at one of his customer sites:

vmkernel: 8:18:59:58.640 cpu2:1410)WARNING: Heap: 1370: Heap_Align(vmfs3, 4096/4096 bytes, 4 align) failed. caller: 0×8fdbd0
vmkernel: 8:18:59:58.640 cpu2:1410)WARNING: Heap: 1266: Heap vmfs3: Maximum allowed growth (24) too small for size (8192)

During the conversation I knew I’d seen this problem before. But the problem that I witnessed was related to a high threshold value in Vizioncore vFoglight. I knew it was possible to change the setting:

1. Open vCenter, and click a specific host
2. Click on the “Configurations” tab
3. Click on Advanced Settings, VMFS3
4. Change the value of “VMFS3.MaxHeapSizeMB”

The default value is 16MB, this allows for a maximum of 4TB of open vmdk’s on a single host. The max setting is 128MB which allows for a maximum of 32TB of open vmdk’s on a single host. Keep this in mind when designing your environment.

Keep in mind that this is ESX 3.5 only, you can’t change the heap size in ESX 3.0.x.

Looked like something that we could all run into.

Full Post http://www.yellow-bricks.com/2008/12/19/heap-size-vmfs3