mirror of https://gitee.com/bigwinds/arangodb
81 lines
2.5 KiB
Markdown
81 lines
2.5 KiB
Markdown
<!-- don't edit here, its from https://@github.com/arangodb/kube-arangodb.git / docs/Manual/ -->
|
|
# Storage
|
|
|
|
An ArangoDB cluster relies heavily on fast persistent storage.
|
|
The ArangoDB Kubernetes Operator uses `PersistentVolumeClaims` to deliver
|
|
the storage to Pods that need them.
|
|
|
|
## Storage configuration
|
|
|
|
In the `ArangoDeployment` resource, one can specify the type of storage
|
|
used by groups of servers using the `spec.<group>.storageClassName`
|
|
setting.
|
|
|
|
The amount of storage needed is configured using the
|
|
`spec.<group>.resources.requests.storage` setting.
|
|
|
|
Note that configuring storage is done per group of servers.
|
|
It is not possible to configure storage per individual
|
|
server.
|
|
|
|
## Local storage
|
|
|
|
For optimal performance, ArangoDB should be configured with locally attached
|
|
SSD storage.
|
|
|
|
The easiest way to accomplish this is to deploy an
|
|
[`ArangoLocalStorage` resource](./StorageResource.md).
|
|
The ArangoDB Storage Operator will use it to provide `PersistentVolumes` for you.
|
|
|
|
The alternative is to create `PersistentVolumes` manually, for all servers that
|
|
need persistent storage (single, agents & dbservers).
|
|
E.g. for a `Cluster` with 3 agents and 5 dbservers, you must create 8 volumes.
|
|
|
|
Note that each volume must have a capacity that is equal to or higher than the
|
|
capacity needed for each server.
|
|
|
|
To select the correct node, add a required node-affinity annotation as shown
|
|
in the example below.
|
|
|
|
```yaml
|
|
apiVersion: v1
|
|
kind: PersistentVolume
|
|
metadata:
|
|
name: volume-agent-1
|
|
annotations:
|
|
"volume.alpha.kubernetes.io/node-affinity": '{
|
|
"requiredDuringSchedulingIgnoredDuringExecution": {
|
|
"nodeSelectorTerms": [
|
|
{ "matchExpressions": [
|
|
{ "key": "kubernetes.io/hostname",
|
|
"operator": "In",
|
|
"values": ["node-1"]
|
|
}
|
|
]}
|
|
]}
|
|
}'
|
|
spec:
|
|
capacity:
|
|
storage: 100Gi
|
|
accessModes:
|
|
- ReadWriteOnce
|
|
persistentVolumeReclaimPolicy: Delete
|
|
storageClassName: local-ssd
|
|
local:
|
|
path: /mnt/disks/ssd1
|
|
```
|
|
|
|
For Kubernetes 1.9 and up, you should create a `StorageClass` which is configured
|
|
to bind volumes on their first use as shown in the example below.
|
|
This ensures that the Kubernetes scheduler takes all constraints on a `Pod`
|
|
that into consideration before binding the volume to a claim.
|
|
|
|
```yaml
|
|
kind: StorageClass
|
|
apiVersion: storage.k8s.io/v1
|
|
metadata:
|
|
name: local-ssd
|
|
provisioner: kubernetes.io/no-provisioner
|
|
volumeBindingMode: WaitForFirstConsumer
|
|
```
|