feat: allow RustFS to validate tenant storage layouts

README.md

@@ -1,6 +1,6 @@
 # RustFS Kubernetes Operator
 
-A Kubernetes operator for [RustFS](https://rustfs.com/) object storage, written in Rust with [kube-rs](https://github.com/kube-rs/kube). It reconciles a **`Tenant` custom resource** (`rustfs.com/v1alpha1`), validates referenced credential and KMS Secrets, and applies RBAC, Services, and StatefulSets so RustFS runs as an erasure-coded cluster inside your cluster.
+A Kubernetes operator for [RustFS](https://rustfs.com/) object storage, written in Rust with [kube-rs](https://github.com/kube-rs/kube). It reconciles a **`Tenant` custom resource** (`rustfs.com/v1alpha1`), validates referenced credential and KMS Secrets, and applies RBAC, Services, and StatefulSets so RustFS runs inside your cluster, from single-node single-disk development tenants to erasure-coded distributed clusters.
 
 **Status:** v0.1.0 pre-release — under active development.
 

console-web/app/(dashboard)/tenants/new/page.tsx

@@ -31,8 +31,8 @@ const DEFAULT_RUSTFS_IMAGE = "rustfs/rustfs:latest"
 
 const defaultPool: CreatePoolRequest = {
   name: "pool-0",
-  servers: 2,
-  volumes_per_server: 2,
+  servers: 1,
+  volumes_per_server: 1,
   storage_size: "10Gi",
   storage_class: "",
 }
@@ -48,9 +48,9 @@ spec:
     name: rustfs-creds
   pools:
     - name: pool-0
-      servers: 2
+      servers: 1
       persistence:
-        volumesPerServer: 2
+        volumesPerServer: 1
         volumeClaimTemplate:
           accessModes:
             - ReadWriteOnce
@@ -474,9 +474,7 @@ export default function TenantCreatePage() {
               <CardHeader className="flex flex-row items-center justify-between">
                 <div>
                   <CardTitle className="text-base">{t("Pools")}</CardTitle>
-                  <CardDescription>
-                    {t("At least one pool with 4+ volumes (e.g. 2 servers × 2 volumes).")}
-                  </CardDescription>
+                  <CardDescription>{t("RustFS validates storage layout when the tenant starts.")}</CardDescription>
                 </div>
                 <Button type="button" variant="outline" size="sm" onClick={addPool}>
                   {t("Add Pool")}

console-web/i18n/locales/en-US.json

@@ -120,7 +120,7 @@
   "Optional": "Optional",
   "Image": "Image",
   "Credentials Secret": "Credentials Secret",
-  "At least one pool with 4+ volumes (e.g. 2 servers × 2 volumes).": "At least one pool with 4+ volumes (e.g. 2 servers × 2 volumes).",
+  "RustFS validates storage layout when the tenant starts.": "RustFS validates storage layout when the tenant starts.",
   "Add Pool": "Add Pool",
   "Pool": "Pool",
   "Remove": "Remove",

console-web/i18n/locales/zh-CN.json

@@ -120,7 +120,7 @@
   "Optional": "可选",
   "Image": "镜像",
   "Credentials Secret": "凭证 Secret",
-  "At least one pool with 4+ volumes (e.g. 2 servers × 2 volumes).": "至少一个池且总卷数不少于 4（例如 2 服务器 × 2 卷）。",
+  "RustFS validates storage layout when the tenant starts.": "RustFS 会在 Tenant 启动时校验存储布局。",
   "Add Pool": "添加存储池",
   "Pool": "存储池",
   "Remove": "移除",

deploy/rustfs-operator/crds/tenant-crd.yaml

@@ -1356,13 +1356,6 @@ spec:
                   - persistence
                   - servers
                   type: object
-                  x-kubernetes-validations:
-                  - messageExpression: '"pool " + self.name + " must have at least 4 total volumes (servers × volumesPerServer)"'
-                    reason: FieldValueInvalid
-                    rule: self.servers * self.persistence.volumesPerServer >= 4
-                  - messageExpression: '"pool " + self.name + " with 3 servers must have at least 6 volumes in total"'
-                    reason: FieldValueInvalid
-                    rule: self.servers != 3 || self.servers * self.persistence.volumesPerServer >= 6
                 maxItems: 32
                 minItems: 1
                 type: array

deploy/rustfs-operator/crds/tenant.yaml

@@ -1356,13 +1356,6 @@ spec:
                   - persistence
                   - servers
                   type: object
-                  x-kubernetes-validations:
-                  - messageExpression: '"pool " + self.name + " must have at least 4 total volumes (servers × volumesPerServer)"'
-                    reason: FieldValueInvalid
-                    rule: self.servers * self.persistence.volumesPerServer >= 4
-                  - messageExpression: '"pool " + self.name + " with 3 servers must have at least 6 volumes in total"'
-                    reason: FieldValueInvalid
-                    rule: self.servers != 3 || self.servers * self.persistence.volumesPerServer >= 6
                 maxItems: 32
                 minItems: 1
                 type: array

docs/operator-user-guide.md

@@ -184,7 +184,7 @@ spec:
     - name: dev-pool
       servers: 1
       persistence:
-        volumesPerServer: 4
+        volumesPerServer: 1
 ```
 
 Apply and verify:
@@ -251,14 +251,15 @@ Key fields:
 | `resources` | Container resource requests and limits for the pool. |
 | `priorityClassName` | Pool-level priority class override. |
 
-Validation rules:
+Operator admission checks:
 
-- `servers * volumesPerServer >= 4`.
-- For `servers: 3`, total volumes must be at least `6`.
+- `servers` and `persistence.volumesPerServer` must be greater than `0`.
 - Pool names must be unique.
 - Pool peer DNS labels must fit Kubernetes DNS label limits.
 - Existing pool `servers` and `volumesPerServer` cannot be changed in place.
 
+The operator does not validate whether a RustFS storage layout, erasure set size, or storage class parity is supported. RustFS performs those checks when the Tenant workload starts.
+
 Example:
 
 ```yaml
@@ -346,6 +347,8 @@ The operator reserves these environment variables and manages them automatically
 - `RUSTFS_CONSOLE_ENABLE`
 - TLS-related RustFS variables when Tenant TLS is enabled.
 
+For a single-pool single-node single-disk Tenant, `RUSTFS_VOLUMES` is rendered as the local data path, for example `/data/rustfs0`. Multi-pool tenants and other layouts render peer DNS URLs through the Tenant headless Service and are validated by RustFS at runtime.
+
 `podDeletionPolicyWhenNodeIsDown` accepts:
 
 - `DoNothing`: do not delete pods automatically.

docs/operator-user-guide.zh-CN.md

@@ -186,7 +186,7 @@ spec:
     - name: dev-pool
       servers: 1
       persistence:
-        volumesPerServer: 4
+        volumesPerServer: 1
 ```
 
 应用并检查：
@@ -253,14 +253,15 @@ Tenant 名称必须兼容 DNS-1035，且长度不超过 55 个字符，因为 Op
 | `resources` | Pool 容器资源 request 和 limit。 |
 | `priorityClassName` | Pool 级 PriorityClass 覆盖。 |
 
-校验规则：
+Operator admission 检查：
 
-- `servers * volumesPerServer >= 4`。
-- 当 `servers: 3` 时，总卷数至少为 `6`。
+- `servers` 和 `persistence.volumesPerServer` 必须大于 `0`。
 - Pool 名称必须唯一。
 - Pool peer DNS label 必须满足 Kubernetes DNS label 长度限制。
 - 已存在 pool 的 `servers` 和 `volumesPerServer` 不能原地修改。
 
+Operator 不校验 RustFS 存储布局、erasure set 大小或 storage class parity 是否被支持。这些检查由 Tenant workload 启动后的 RustFS 自行完成。
+
 示例：
 
 ```yaml
@@ -348,6 +349,8 @@ Operator 会自动管理以下环境变量：
 - `RUSTFS_CONSOLE_ENABLE`
 - 启用 TLS 时的 RustFS TLS 相关变量
 
+对于单 pool 的单节点单盘 Tenant，`RUSTFS_VOLUMES` 会渲染为本地数据路径，例如 `/data/rustfs0`。多 pool Tenant 和其他布局仍会通过 Tenant headless Service 渲染 peer DNS URL，并由 RustFS 在运行时校验。
+
 `podDeletionPolicyWhenNodeIsDown` 支持以下值：
 
 - `DoNothing`：不自动删除 Pod。

examples/README.md

@@ -8,7 +8,7 @@ This directory contains example Tenant configurations for the RustFS Kubernetes
 
 | Example | Use Case | Complexity | Storage | Best For |
 |---------|----------|------------|---------|----------|
-| [minimal-dev-tenant.yaml](./minimal-dev-tenant.yaml) | Development/Learning | ⭐ Simple | 40Gi | **Start here** if new |
+| [minimal-dev-tenant.yaml](./minimal-dev-tenant.yaml) | Development/Learning | ⭐ Simple | 10Gi | **Start here** if new |
 | [simple-tenant.yaml](./simple-tenant.yaml) | Documentation Reference | ⭐⭐ Moderate | Configurable | Learning all options |
 | [secret-credentials-tenant.yaml](./secret-credentials-tenant.yaml) | Secret-based Credentials | ⭐ Simple | Configurable | **Production credential security** |
 | [provisioning-tenant.yaml](./provisioning-tenant.yaml) | Policy/User/Bucket Provisioning | ⭐⭐ Moderate | 40Gi | Tenant bootstrap automation |
@@ -46,8 +46,8 @@ This directory contains example Tenant configurations for the RustFS Kubernetes
 **Smallest valid configuration** for learning, testing, and local development.
 
 **Configuration:**
-- 1 server × 4 volumes = 4 total volumes (minimum valid)
-- 40Gi total storage (4 × 10Gi default)
+- 1 server × 1 volume = 1 total volume (single-node single-disk)
+- 10Gi total storage (1 × 10Gi default)
 - Debug logging enabled
 
 **Use case:** Local development, learning the operator, quick testing.
@@ -64,7 +64,7 @@ kubectl apply -f examples/minimal-dev-tenant.yaml
 Single-pool tenant with **comprehensive comments** explaining all available options.
 
 **Features demonstrated:**
-- Basic pool configuration with validation
+- Basic pool configuration and admission checks
 - Persistence settings with volume claim templates
 - Custom labels and annotations for PVCs
 - Environment variable configuration
@@ -369,7 +369,6 @@ spec:
       servers: <number>              # Must be > 0
       persistence:
         volumesPerServer: <number>   # Must be > 0
-        # Validation: servers * volumesPerServer >= 4
 
   # Optional fields
   env: [...]
@@ -378,31 +377,22 @@ spec:
   # ... see Tenant CRD for all fields
 ```
 
-## Validation Rules
+## Admission Checks
 
 ### Pool Requirements
 
-- **Minimum total volumes**: `servers * volumesPerServer >= 4` (RustFS erasure coding requirement)
-- **Three-server pools**: `servers * volumesPerServer >= 6` (stricter than the general minimum)
 - **Server count**: Must be > 0
 - **Volumes per server**: Must be > 0
 - **Pool name**: Must not be empty
 
-These rules are enforced by the Tenant CRD (CEL) and the operator console API.
+The operator intentionally does not validate RustFS storage topology, erasure set sizing, or parity compatibility. Those checks are left to RustFS when the Tenant starts.
 
-### Valid Examples
+### Layout Examples
 
-✅ `servers: 4, volumesPerServer: 1` → 4 total volumes
-✅ `servers: 2, volumesPerServer: 2` → 4 total volumes
-✅ `servers: 3, volumesPerServer: 2` → 6 total volumes (minimum for 3 servers)
-✅ `servers: 4, volumesPerServer: 4` → 16 total volumes
-
-### Invalid Examples
-
-❌ `servers: 2, volumesPerServer: 1` → 2 total volumes (< 4)
-❌ `servers: 1, volumesPerServer: 1` → 1 total volume (< 4)
-❌ `servers: 3, volumesPerServer: 1` → 3 total volumes (< 6 for 3 servers)
-❌ `servers: 0, volumesPerServer: 4` → Server count must be > 0
+- `servers: 1, volumesPerServer: 1` → single-node single-disk style
+- `servers: 2, volumesPerServer: 1` → passed through to RustFS
+- `servers: 3, volumesPerServer: 1` → passed through to RustFS
+- `servers: 4, volumesPerServer: 4` → distributed style
 
 ## Common Configurations
 
@@ -414,7 +404,7 @@ spec:
     - name: dev
       servers: 1
       persistence:
-        volumesPerServer: 4  # 1 * 4 = 4 (minimum valid)
+        volumesPerServer: 1  # single-node single-disk
 ```
 
 ### Production (High Availability)
@@ -511,9 +501,9 @@ kubectl logs -n rustfs-system -l app=rustfs-operator
 ### Validation Errors
 
 Common issues:
-- Pool validation: Ensure `servers * volumesPerServer >= 4`
 - Empty pool name
 - Zero servers or volumes
+- RustFS rejecting an unsupported storage layout after the Tenant starts
 
 ### Pods Not Starting
 

examples/minimal-dev-tenant.yaml

@@ -5,11 +5,11 @@
 #
 # Resources created:
 # - 1 StatefulSet with 1 replica
-# - 4 PVCs (1 server × 4 volumes)
+# - 1 PVC (1 server × 1 volume)
 # - 3 Services (IO at 9000, Console at 9001, Headless)
 # - RBAC resources (Role, ServiceAccount, RoleBinding)
 #
-# Total storage: 40Gi (4 volumes × 10Gi default)
+# Total storage: 10Gi (1 volume × 10Gi default)
 
 apiVersion: rustfs.com/v1alpha1
 kind: Tenant
@@ -22,14 +22,14 @@ spec:
   # Container image (optional - uses operator default if not specified)
   image: rustfs/rustfs:latest
 
-  # Minimal pool configuration
-  # servers * volumesPerServer must be >= 4 (RustFS erasure coding requirement)
-  # This uses: 1 server × 4 volumes = 4 total volumes (minimum valid)
+  # Minimal pool configuration.
+  # A single-node single-disk Tenant is expressed as 1 server × 1 volume.
+  # Other storage layouts are passed through to RustFS for validation at startup.
   pools:
     - name: dev-pool
       servers: 1  # Single server for development
       persistence:
-        volumesPerServer: 4  # Minimum 4 volumes required
+        volumesPerServer: 1  # Single PVC; RustFS uses no erasure parity
 
         # Optional: Reduce storage size for development
         # volumeClaimTemplate:
@@ -61,7 +61,7 @@ spec:
 #   kubectl wait --for=condition=ready pod -l rustfs.tenant=dev-minimal --timeout=300s
 
 # 4. Access S3 API (port 9000):
-#   kubectl port-forward svc/rustfs 9000:9000
+#   kubectl port-forward svc/dev-minimal-io 9000:9000
 #   # Test: aws --endpoint-url http://localhost:9000 s3 ls
 
 # 5. Access Console UI (port 9001):
@@ -74,10 +74,10 @@ spec:
 #     -o jsonpath='{.spec.template.spec.containers[0].env[?(@.name=="RUSTFS_VOLUMES")].value}'
 #
 # Output will be:
-#   http://dev-minimal-dev-pool-0.dev-minimal-hl.default.svc.cluster.local:9000/data/rustfs{0...3}
+#   /data/rustfs0
 #
-# This tells RustFS to use 4 volumes at paths:
-#   /data/rustfs0, /data/rustfs1, /data/rustfs2, /data/rustfs3
+# This tells RustFS to use one local volume at:
+#   /data/rustfs0
 
 # 7. Test with MinIO client:
 #   mc alias set devlocal http://localhost:9000 rustfsadmin rustfsadmin

examples/simple-tenant.yaml

@@ -12,15 +12,14 @@ spec:
   podManagementPolicy: Parallel
 
   # Pool configuration - at least one pool is required
-  # Each pool must have: servers * volumesPerServer >= 4
+  # RustFS validates whether the requested storage layout is supported at startup.
   pools:
     - name: primary
       servers: 2
 
       # Persistence configuration for storage (REQUIRED)
-      # Note: servers * volumesPerServer must be >= 4 for RustFS distributed storage
       persistence:
-        # Number of volumes per server (REQUIRED, must satisfy servers * volumesPerServer >= 4)
+        # Number of volumes per server (REQUIRED)
         volumesPerServer: 2
 
         # Optional: Path where volumes will be mounted in the container (defaults to /data)
@@ -99,9 +98,10 @@ spec:
       # Optional: Priority class - overrides tenant-level priority
       # priorityClassName: high-priority
 
-  # Multi-Node Communication (Automatic)
+  # Volume Configuration (Automatic)
   # The operator automatically generates the RUSTFS_VOLUMES environment variable
-  # for multi-node, multi-disk distributed storage communication.
+  # for the selected layout. Single-pool single-node single-disk tenants use a
+  # local path, while multi-pool and distributed layouts use peer DNS.
   #
   # For this configuration, the generated RUSTFS_VOLUMES will be:
   # http://example-tenant-primary-{0...1}.example-tenant-hl.rustfs-system.svc.cluster.local:9000/data/rustfs{0...1}

examples/spot-instance-tenant.yaml

@@ -294,7 +294,7 @@ spec:
 # Best Practices:
 
 # 1. Maintain minimum on-demand capacity:
-#    - At least servers × volumesPerServer >= 4 on on-demand
+#    - Keep enough on-demand RustFS capacity for the layout you choose
 #    - Ensures cluster survives even if all spot instances interrupted
 
 # 2. Use topology spread for spot pools:

examples/tenant-4nodes.yaml

@@ -1,5 +1,5 @@
 # RustFS Tenant - 4-node distributed deployment (Kind multi-node + local storage)
-# Architecture: 4 servers x 2 volumes = 8 drives (servers * volumesPerServer >= 4)
+# Architecture: 4 servers x 2 volumes = 8 drives
 # Requires: kind-rustfs-cluster (3 workers), StorageClass local-storage, 12 PVs
 apiVersion: rustfs.com/v1alpha1
 kind: Tenant