Error "An error occurred while taking a snapshot: Out of resources" during snapshot operations

Products

VMware vSAN

Issue/Introduction

When trying to create a snapshot of a VM residing on a vSAN datastore, it fails with the error:

There are currently 1 usable fault domains. The operation requires 2 more usable fault domains.
An error occurred while taking a snapshot: Out of resources.

Or 

No disks of required version is present in the cluster for this operation to succeed. An error occurred while taking a snapshot: Out of resources.

Hostd.log

2025-11-29T11:10:41.652Z verbose hostd[2101866] [Originator@6876 sub=Vigor.Vmsvc.vm:/vmfs/volumes/vsan:################/##################/<VM name>=#####################] Create Snapshot message: There are currently X

usable fault domains. The operation requires 1 more usable fault domains.
--> An error occurred while taking a snapshot: Out of resources.

var/log/clomd.log

2025-04-15T14:47:00.776Z No(29) clomd[2098465]: [Originator@6876 opID=1804296191] CLOMLogConfigurationPolicy: Object size 322122547200 bytes with policy: (("stripeWidth" i1) ("cacheReservation" i0)("proportionalCapacity" (i0 i100)) (
"hostFailuresToTolerate" i1) ("forceProvisioning" i0) ("spbmProfileId" "aa6d5a82-1c88-45da-85d3-############") ("spbmProfileGenerationNumber" l+0) ("objectVersion" i20) ("CSN" l4584) ("SCSN" l4581) ("spbmProfileName" "vSAN Default Storage Policy"))
2025-04-15T14:47:00.776Z No(29) clomd[2098465]: [Originator@6876 opID=1804296191] CLOMGetMinMaxObjVersion: minVersion: 20 maxVersion: 20
2025-04-15T14:47:00.777Z Cr(26) clomd[2098465]: [Originator@6876 opID=1804296191] CLOM_CheckClusterResourcesForPolicy: Not enough Upper FD's available. Available: 2, needed: 3
2025-04-15T14:47:00.777Z Cr(26) clomd[2098465]: [Originator@6876 opID=1804296191] CLOM_GenerateObjectConfig: Cluster doesn't have resources for the current iteration: objVersion: 20 replicas: 1, stripes: 1
2025-04-15T14:47:00.777Z Cr(26) clomd[2098465]: [Originator@6876 opID=1804296191] CLOMGenerateNewConfig: Failed to generate a configuration: Not found
2025-04-15T14:47:00.777Z Cr(26) clomd[2098465]: [Originator@6876 opID=1804296191] CLOM_Diagnose: No disks of required version is present in the cluster for this operation to succeed.
2025-04-15T14:47:00.777Z Cr(26) clomd[2098465]: [Originator@6876 opID=1804296191] CLOMProcessWorkItem: Failed to generate configuration: Underlying device has no free space
2025-04-15T14:47:00.777Z No(29) clomd[2098465]: [Originator@6876 opID=1804296191] CLOMProcessWorkItem: Op ends:1804296191

Environment

7.x,8.x

Cause

The infrastructure does not have the sufficient number of of Fault Domains for component placement. This could be due to a host still in vSAN Decom or hardware failure reducing the number of fault domains.

Example 1:

3-node Cluster with 3 Fault Domains (1 Host per FD).
One host has been placed in to MM or has failed and when you try to create a snapshot.
"There are currently 2 usable fault domains. The operation requires 1 more usable fault domains."

Example 2:

4-node Cluster with 4 Fault Domains (1 Host per FD). Running Raid-5
One host has been placed in to MM or has failed and when you try to create a snapshot.
"There are currently 3 usable fault domains. The operation requires 1 more usable fault domains."

Example 3:

24-node Cluster with 3 Fault Domains (= 8 Hosts per FD).
All Hosts in one Fault Domain are being shut down.
"There are currently 2 usable fault domains. The operation requires 1 more usable fault domains."

Please refer to the following documentation regarding Fault Domains for further information on vSAN cluster sizing.

For safety reasons, in its default configuration vSAN will not allow the provisioning of new objects if there are not enough resources to satisfy the applied storage policy.

Resolution

Verify if there are any hosts in Decom State.

echo "hostname,decomState,decomJobType";for host in $(cmmds-tool find -t HOSTNAME -f json |grep -B2 Healthy|grep uuid|awk -F \" '{print $4}');do hostName=$(cmmds-tool find -t HOSTNAME -f json -u $host|grep content|awk -F \" '{print $6}');decomInfo=$(cmmds-tool find -t NODE_DECOM_STATE -f json -u $host |grep content|awk '{print $3 $5}'|sed 's/,$//');echo "$hostName,$decomInfo";done|sort

Sample output:

hostname,decomState,decomJobType

esxi-1.example.com,0,0
esxi-2.example.com,0,0
esxi-3.example.com,0,0

Anything other than 0 means there is a host in vSAN Decom State.

hostname,decomState,decomJobType

esxi-1.example.com,0,0
esxi-2.example.com,0,0
esxi-3.example.com,6,0 <--- host is in Decom State

If you find a host in Decom State, place the host into maintenance mode ('No Action' option), and then remove the host from maintenance mode using the host UI or vCenter UI to clear this state. See KB vSAN Host Maintenance Mode is not in sync with vSAN Node Decommission State

Workaround

Note: The below workaround is only a temporary fix while waiting for failed hardware to be replaced. The advanced setting "/VSAN/ClomForceProvisionPlacements" should not be left permanently enabled as your data won't be properly protected for redundancy, which can lead to data unavailability or even data loss.

For vSAN 6.7 onwards the following workaround is available:

Set the advanced config option on all Hosts to be able to create/revert snapshots until the Fault Domain issue has been resolved:
esxcfg-advcfg -s 1 /VSAN/ClomForceProvisionPlacements
Once the Fault Domain issue has been resolved, revert the setting back on all Hosts by:
esxcfg-advcfg -s 0 /VSAN/ClomForceProvisionPlacements

Please keep in mind that in this case, objects can be created even if they do not satisfy the requirements of a specific storage policy, so it is recommended to change this back after the host is back online again.

Additional Information

See also: VMware vSAN Design Guide page 9 Designing for Capacity Maintenance and Availability