vSAN 7 four-nodes cluster - The host cannot enter maintenance mode.

[nblr06]

Just encountered a situation in my vSAN (esxi version 7.0.3, 19193900) cluster of 4 nodes.

When I perform "full data migration" precheck for a host to enter maintenance mode, the result is negative, as shown below:

The host cannot enter maintenance mode.
1 more standalone host is required. Some objects will become inaccessible or non-compliant with their storage policy.

I checked the VMs that are residing in this cluster and they all use the "vsan default storage policy".

This is strange.

does anyone know why? or any clues to trace objects that cause this?

[TheBobkin]

@nblr06  "vsan default storage policy" is merely a name - that policy can have rules changed to anything - please check is this currently RAID5 or not (as RAID5 requires 4 nodes for placement e.g. FDM not possible with only 4 nodes).

Do all nodes have storage? Are any of them in Devon state? Check Skyline Health.

[nblr06]

I solved it. 

Thanks for the hints. 

I found an object which was using raid-5 policy that blocked ESXi host from entering maintenance mode and this is the root cause.