Mr. Epping over at Yellow-Bricks posted this on VMFS3 Heap Size. Iâ€™m reposting here for future reference.
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: 0Ã—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 Iâ€™d seen this problem before. But the problem that I witnessed was related to a high threshold value in Veeam vFoglight. I knew it was possible to change the setting:
1. Open vCenter, and click a specific host
2. Click on the â€œConfigurationsâ€ tab
3. Click on VMFS3
4. Change the value of â€œVMFS3.MaxHeapSizeMBâ€
The default value is 16MB, this allows for a maximum of 4TB of open vmdkâ€™s on a single host. The max setting is 128MB which allows for a maximum of 32TB of open vmdkâ€™s on a single host. Keep this in mind when designing your environment.
Keep in mind that this is ESX 3.5 only, you canâ€™t change the heap size on ESX 3.0.x