Architecting VMware vSAN 6.2 : vSAN Introduction : 2.3 vSAN Internal Architecture : 2.3.1 The Cluster-Level Object Manager (CLOM)
   
2.3.1 The Cluster-Level Object Manager (CLOM)
The CLOM exists as a userspace daemon on each ESXi host in the vSAN cluster and is responsible for:
Orchestrating objects.
Placement of objects during create operations.
Ensuring that component placement satisfies the defined storage policy.
Scheduling rebuilds should a component need to be replaced.
o With a placement operation, it verifies that policies are satisfied.
o If an object is reconfigured with a new storage policy, the CLOM handles the placement of any new components required.