vSAN disk groups not mounted due to insufficient memory on the ESXi

Products

• VMware vSAN

Issue/Introduction

Symptoms:

Disk Group on host shows in unhealthy state and unmounted in the disk management pane.

After the disk group is recreated it goes into unhealthy/unmounted state, and you will see the following messages in the  vmkernel log:

Creating diskgroup uuid: 52931bf3-xxxx-xxxx-xxxx-xxxxxxxxxxxx (Read cache size: 7037252866048, Write buffer on-disk size: 644245086208, Write buffer in-memory siz$
2024-12-31T11:39:17.276Z In(182) vmkernel: cpu88:877016 opID=5fdbe6a2)Admission failure in path: host:system:drivers:vsanapi-8:LSOMDiskGroup_002
2024-12-31T11:39:17.276Z In(182) vmkernel: cpu88:877016 opID=5fdbe6a2)LSOMDiskGroup_002 (2268750) extraMin/extraFromParent: 2557290/2553194, host (0) childEmin/eMinLimit: 6377439/8279455
2024-12-31T11:39:17.276Z Wa(180) vmkwarning: cpu88:877016 opID=5fdbe6a2)WARNING: LSOMCommon: LSOM_DiskGroupCreate:2750: Failed to create a 9989 MB page pool for disk group 52931bf3-xxxx-xxxx-xxxx-xxxxxxxxxxxx
2024-12-31T11:39:17.354Z In(182) vmkernel: cpu88:877016 opID=5fdbe6a2)LSOMCommon: LSOMVA_CloseDiskGroup:1158: Unmapped all of the 2.5 GB. It required 0 unmaps
2024-12-31T11:39:17.354Z In(182) vmkernel: cpu88:877016 opID=5fdbe6a2)LSOMCommon: LSOMVA_CloseDiskGroup:1205: Handle 0 is pending removal
2024-12-31T11:39:17.477Z Wa(180) vmkwarning: cpu88:877016 opID=5fdbe6a2)WARNING: PLOG: PLOGInitDiskGroupMemory:8336: Failed to initialize the memory for the diskgroup 52931bf3-xxxx-xxxx-xxxx-xxxxxxxxxxxx: Admission check failed for memory resource

Environment

VMware vSAN 6.x
VMware vSAN 7.x
VMware vSAN 8.x

Cause

This is caused by low physical memory on the ESXi host.

Resolution

Add more physical memory to the ESXi host to meet the vSAN memory requirements.

To understand memory requirement in vSAN refer to this article: https://knowledge.broadcom.com/external/article/314302/understanding-vsan-memory-consumption-in.html