Local volume¶
Using HwameiStor can run stateful applications very easily.
Here we use a MySQL application as an example.
Note
The MySQL Yaml file below is from Kubernetes official repo
View StorageClass
¶
HwameiStor's Helm charts will install a StorageClass
named hwameistor-storage-lvm-hdd
by default, which can create local volumes.
Run the following command to open the YAML file.
Modify the following YAML file.
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: hwameistor-storage-lvm-hdd
parameters:
convertible: "false"
csi.storage.k8s.io/fstype:xfs
poolClass: HDD
poolType: REGULAR
replicaNumber: "1"
striped: "true"
volumeKind: LVM
provisioner: lvm.hwameistor.io
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer
allowVolumeExpansion: true
If this storageClass
was not generated during installation, run the following yaml file to regenerate it:
Create StatefulSet
¶
After HwameiStor and StorageClass
are ready, one command can create MySQL container and its data volume:
Note that volumeClaimTemplates
uses storageClassName: hwameistor-storage-lvm-hdd
:
spec:
volumeClaimTemplates:
- metadata:
name: data
labels:
app: sts-mysql-local
app.kubernetes.io/name: sts-mysql-local
spec:
storageClassName: hwameistor-storage-lvm-hdd
accessModes: ["ReadWriteOnce"]
resources:
requests:
storage: 1Gi
and schedulerName: hwameistor-scheduler
:
View MySQL container and PVC/PV
¶
In this example, the MySQL container is scheduled to node k8s-worker-3
.
$ kubectl get po -l app=sts-mysql-local -o wide
NAME READY STATUS RESTARTS AGE IP NODE
sts-mysql-local-0 2/2 Running 0 3m08s 10.1.15.154 k8s-worker-3
$ kubectl get pvc -l app=sts-mysql-local
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGE CLASS AGE VOLUME MODES
data-sts-mysql-local-0 Bound pvc-accf1ddd-6f47-4275-b520-dc317c90f80b 1Gi RWO hwameistor-storage-lvm-hdd 3m Filesystem
View the LocalVolume
object¶
By viewing LocalVolume(LV)
with the same name as PV
, you can see that the local volume is created on the node k8s-worker-3
:
$ kubectl get lv pvc-accf1ddd-6f47-4275-b520-dc317c90f80b
NAME POOL REPLICAS CAPACITY ACCESSIBILITY STATE RESOURCE PUBLISHED AGE
pvc-accf1ddd-6f47-4275-b520-dc317c90f80b LocalStorage_PoolHDD 1 1073741824 Ready-1 k8s-worker-3 3m
[Optional] Scale the MySQL application into a three-node cluster¶
HwameiStor supports the horizontal expansion of StatefulSet
. StatefulSet
container will mount an independent local volume:
$ kubectl scale sts/sts-mysql-local --replicas=3
$ kubectl get po -l app=sts-mysql-local -o wide
NAME READY STATUS RESTARTS AGE IP NODE
sts-mysql-local-0 2/2 Running 0 4h38m 10.1.15.154 k8s-worker-3
sts-mysql-local-1 2/2 Running 0 19m 10.1.57.44 k8s-worker-2
sts-mysql-local-2 0/2 Init:0/2 0 14s 10.1.42.237 k8s-worker-1
$ kubectl get pvc -l app=sts-mysql-local -o wide
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGE CLASS AGE VOLUME MODES
data-sts-mysql-local-0 Bound pvc-accf1ddd-6f47-4275-b520-dc317c90f80b 1Gi RWO hwameistor-storage-lvm-hdd 3m07s Filesystem
data-sts-mysql-local-1 Bound pvc-a4f8b067-9c1d-450f-aff4-5807d61f5d88 1Gi RWO hwameistor-storage-lvm-hdd 2m18s Filesystem
data-sts-mysql-local-2 Bound pvc-47ee308d-77da-40ec-b06e-4f51499520c1 1Gi RWO hwameistor-storage-lvm-hdd 2m18s Filesystem
$ kubectl get lv
NAME POOL REPLICAS CAPACITY ACCESSIBILITY STATE RESOURCE PUBLISHED AGE
pvc-47ee308d-77da-40ec-b06e-4f51499520c1 LocalStorage_PoolHDD 1 1073741824 Ready-1 k8s-worker-1 2m50s
pvc-a4f8b067-9c1d-450f-aff4-5807d61f5d88 LocalStorage_PoolHDD 1 1073741824 Ready-1 k8s-worker-2 2m50s
pvc-accf1ddd-6f47-4275-b520-dc317c90f80b LocalStorage_PoolHDD 1 1073741824 Ready-1 k8s-worker-3 3m40s