A vSAN administrator has recently upgraded a vSAN cluster to 8.0 OSA and has enabled Capacity Reserve features to reduce the amount of capacity reserved for transient and rebuild operations.
Which scenario would prevent this feature from operating properly?
When the used space on the vSAN datastore exceeds the suggested slack rebuild threshold, it would prevent the Capacity Reserve feature from operating properly. This is because the slack rebuild threshold is designed to ensure that there is enough space to handle rebuild and other transient operations. If the used space exceeds this threshold, vSAN may not have adequate capacity to perform these necessary tasks, leading to operational issues.
B. https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vsan-monitoring.doc/GUID-CD510EAE-1A9F-45D2-BB66-E893C8AAF20A.html
vSAN requires capacity for its internal operations. For a cluster to be able to tolerate a single host failure, vSAN requires free space to restore the data of the failed host. The capacity required to restore a host failure matches the total capacity of the largest host in the cluster. These values are represented as thresholds in the Capacity Monitor page: Operations threshold - Displays the space vSAN requires to run its internal operations in the cluster. If the used space exceeds the operations threshold, vSAN might not operate properly. Host rebuild threshold - Displays the space vSAN requires to tolerate one host failure. If the used space exceeds the host rebuild threshold and the host fails, vSAN might not successfully restore all data from the failed host. https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vsan-monitoring.doc/GUID-CD510EAE-1A9F-45D2-BB66-E893C8AAF20A.html