depths-oq31yn had a three-replica database. The StatefulSet db was deleted. Three more storage faults sit next to it. Fix them in any order.

kubectl get sts,pods,pvc -n depths-oq31yn
kubectl get pv

sts db           gone
pvc data-db-0..2 Bound    (data intact)
pv  archive-pv   Released (claim deleted, Retain)
pvc cache        Pending  (market-api cannot start)
sts cache        template redis:7.4, Pods still redis:7.2

Bring the database back

The original manifest is at ~/depths-oq31yn/db.yaml. Read it first:

cat ~/depths-oq31yn/db.yaml

A StatefulSet with the same name and the same volumeClaimTemplates names the same claims: data-db-0, data-db-1, data-db-2. They exist and are Bound, so the controller does not create new ones and the Pods mount the old volumes.

kubectl apply -f ~/depths-oq31yn/db.yaml
kubectl get sts,pods,pvc -n depths-oq31yn

Reclaim the archive volume

archive-pv is Released. A claim archive-restore is waiting for it. Clear the stale reference:

kubectl patch pv archive-pv -p '{"spec":{"claimRef":null}}'
kubectl get pv archive-pv

Fix the cache claim

market-api is Pending because its claim cache is Pending:

kubectl describe pvc cache -n depths-oq31yn

The class name in ~/depths-oq31yn/api.yaml is misspelled. A claim's class cannot be changed in place: fix the file, delete the claim, apply the file. The Deployment's Pod is the first consumer, so the claim binds and the Pod starts.

Finish the cache update

The cache StatefulSet's template says redis:7.4; its Pods still run redis:7.2:

kubectl get sts cache -n depths-oq31yn -o jsonpath='{.spec.updateStrategy}'
kubectl get pods -n depths-oq31yn -l app=cache -o jsonpath='{.items[*].spec.containers[0].image}'

The partition equals the replica count, so no ordinal is updated. Lower it to 0 and the update runs from cache-1 down to cache-0:

kubectl patch sts cache -n depths-oq31yn -p '{"spec":{"updateStrategy":{"rollingUpdate":{"partition":0}}}}'
kubectl rollout status sts cache -n depths-oq31yn

The last objective is a question: after a StatefulSet scales down, which object still holds the removed Pod's data?