How the PVC claims the corresponding PV rightly? I see PVC YAML file doesn’t have PV details, so how this connection mechanism works?
1 Answers
PVCs look for a PV that satisfies the requirements of its .spec section and will select one that fits. In this lesson, the PVC .spec sections lists the following requirements:
gke-pvc.yml
spec:
accessModes:
- ReadWriteOnce
storageClassName: ssd
resources:
requests:
storage: 20GiIn order for a PV to be selected by this PVC, it would need to satisfy each of the listed requirements:
– The access mode must be ReadWriteOnce.
– The storage class must be SSD.
– The storage capacity must be at least 20GB.
The PV from this lesson lists the following in its .spec section:
gke-pv.yml
spec:
accessModes:
- ReadWriteOnce
storageClassName: ssd
capacity:
storage: 20Gi
persistentVolumeReclaimPolicy: Retain
gcePersistentDisk:
pdName: uber-diskWe can see that this PV matches all of the requirements listed in the PVC:
– The access mode is ReadWriteOnce.
– The storage class is SSD.
– The capacity is 20GB.
Because it matches the requirements, the PVC will select this PV.
The video goes over this with a side-by-side comparison starting around the 5:35 mark.
Use Labels in the definition of PV and then use the labels in PVC in Selector to be able to select a specific volume. This is going to be most useful at scale