An administrator is troubleshooting a vSAN issue. As part of the initial investigation, the following observations were identified:
* vSAN cluster capacity is decreased.
* Some virtual machine components are marked as degraded.
* Component rebuild process started automatically.
What is the cause of this issue?
The symptoms described---reduced cluster capacity, degraded virtual machine components, and automatic component rebuild operations---are classic indicators of a vSAN disk failure or disk group degradation. vSAN continuously monitors the health of disks, disk groups, and network paths. When a physical disk or disk group becomes unavailable, vSAN will:
Mark affected components as degraded because the required number of replicas or witnesses cannot be maintained.
Trigger automatic repair/rebuild operations, provided there are enough healthy disks remaining in the cluster to satisfy the storage policy (e.g., FTT=1, RAID1/5/6).
Reduce available storage capacity because the failed device is removed from contributing to the vSAN datastore.
These behaviors align directly with documented vSAN failure-response logic, which states that component rebuilds begin automatically after a disk failure, assuming the cluster still has adequate resources.
The other options do not match the symptoms:
A . VM migration to another cluster does not reduce vSAN capacity nor trigger component rebuilds.
B . vSAN license capacity too small restricts features, not component state or capacity changes.
C . Too many VMs created may cause capacity pressure but does not mark components degraded or trigger automated rebuilds.
Only physical disk failure accurately explains all three observations simultaneously.
Gladis
21 days ago