Skip to content

Clarify Pool-generated StorageClass parameters, drop dead ndcs/npcs #194

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
boddumanohar wants to merge 1 commit into
base: main
Choose a base branch
from
Open

Clarify Pool-generated StorageClass parameters, drop dead ndcs/npcs #194

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 10 additions & 2 deletions docs/kubernetes/installation/k8s-storage-plane.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -206,8 +206,16 @@ Once the pool is active, the operator automatically creates a StorageClass named
`simplyblock-<namespace>-<clusterName>-<poolName>`. In this example, the StorageClass is called
`simplyblock-simplyblock-cluster-production-pool`.

The StorageClass is automatically removed when the storage pool is deleted. For full details and customization options
are available at [Simplyblock Operator: Storage Pool](../../reference/operator/reference.md#pool).
`cluster_id` and `pool_name` are set from the pool and cannot be overridden. The remaining StorageClass
parameters are copied from `spec.storageClassParameters`. See
[Storage Class: StorageClass Created by a Pool](../usage/storage-class.md#storageclass-created-by-a-pool) for
the full parameter mapping.

A StorageClass's parameters cannot be changed after creation, so `spec.storageClassParameters` is immutable
once the pool is created. A new pool is required to provision volumes with different defaults.

The StorageClass is automatically removed when the storage pool is deleted. Full details and customization
options are available at [Simplyblock Operator: Storage Pool](../../reference/operator/reference.md#pool).

```bash title="Check the StorageClass"
kubectl get storageclass simplyblock-simplyblock-production-my-pool
Expand Down
20 changes: 16 additions & 4 deletions docs/kubernetes/usage/storage-class.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,19 @@ simplyblock control plane to provision a logical volume matching the requested s
the complexity of volume creation and ensures that workloads running in Kubernetes receive high-performance, resilient
block storage directly backed by simplyblock.

## StorageClass Created by a Pool

A StorageClass named `simplyblock-<namespace>-<clusterName>-<poolName>` is created automatically by the operator once
a `Pool` resource becomes active, as described in
[Create a Storage Pool](../installation/k8s-storage-plane.md#create-a-storage-pool). `cluster_id` and `pool_name` are
always set from the pool and cannot be overridden. The rest of the parameters are copied from
`Pool.spec.storageClassParameters`. Defaults for each field are listed at
[Simplyblock Operator: Pool](../../reference/operator/reference.md#storageclassparameters).

Kubernetes does not allow the `parameters` of a StorageClass to be changed after creation, so
`Pool.spec.storageClassParameters` is immutable once the pool is created. There is no supported way to reconfigure
the generated StorageClass afterward. A new pool has to be created to provision volumes with different defaults.

## Example Usage

A typical simplyblock StorageClass contains the name of the storage class, a filesystem type to automatically format
Expand All @@ -47,8 +60,8 @@ allowVolumeExpansion: true

## StorageClass Parameters

Each cluster has a default schema, but each volume can optionally use an alternative schema. However, the schema must
"fit" into the cluster, meaning `n+k` must be equal to (or better smaller) than the number of nodes in the cluster.
The erasure coding schema (the number of data and parity chunks per stripe) is set once at cluster creation and
applies to all volumes in the cluster. It cannot be configured per volume or through a StorageClass.

See the [Erasure Coding Configuration](../../deployment-preparation/erasure-coding-scheme.md) for more details.

Expand Down Expand Up @@ -78,8 +91,7 @@ If `namespace-volumes` is set to `yes`, the number of namespaces per subsystem h
| qos_w_mbytes | int | Defines the maximum write throughput in megabytes reserved for a logical volume of this storage class. A zero (0) means no maximum. | true | 0 |
| compression | bool | Defines if the logical volume of this storage class will be stored compressed or not. | true | false |
| encryption | bool | Defines if the logical volume of this storage class will be encrypted or not. | true | false |
| distr_ndcs | int | Defines the number of data chunks for the erasure coding scheme. | true | 1 |
| distr_npcs | int | Defines the number of parity chunks for the erasure coding scheme. | true | 1 |
| replicate | bool | Defines if the logical volume of this storage class will be replicated. | true | false |
| lvol_priority_class | int | Defines the priority class of a logical volume of this storage class. | true | 0 |
| max_namespace_per_subsys | int | Defines the number of namespaces per NVMe subsystem. | true | 1 |
| tune2fs_reserved_blocks | int | Defines the number of reserved blocks for tune2fs operations. | true | 0 |
Loading