Storage pools and volumes

Instance disks live in storage pools. A storage pool is a block of disk capacity that the operator sets up on the compute hosts; you cannot create or change pools yourself. Inside a pool you can create volumes: extra disks, separate from an instance's root disk, that you attach to instances and that survive when an instance is deleted.

Pools are managed by the operator. Volumes are managed through the API; the dashboard shows the disks attached to each instance.

Storage pools

Every instance's root disk comes from a pool. The default profile places the root disk on the operator's first storage pool, without a size limit. There is no API to list pools, so ask your operator which pool names you can use. On many installations the pool is called default, which is also the pool the volume API uses when you do not name one.

To give a new instance a root disk with a size limit, set a root disk device that names the pool when you create it:

{	"name": "db-1",	"imageAlias": "debian/12",	"devices": {		"root": { "type": "disk", "path": "/", "pool": "default", "size": "40GiB" }	}}

The size of this root device counts toward your tenant's disk quota. A root device without pool is ignored.

See an instance's disks

Open the instance and select the Storage tab. Disks lists every disk in force: the root disk plus any attached volumes or mounts, including ones that come from profiles. For each disk you see the Mount path, the Pool, the Size limit (no limit when none is set) and, while the instance is running, how much is Used.

Create a volume

POST /api/v1/compute/storage creates a volume. Only name is required (1 to 63 characters, unique in the tenant); poolName defaults to default.

curl -X POST https://lahijan.example.com/api/v1/compute/storage \  -H "Authorization: Bearer $LAHIJAN_TOKEN" \  -H "X-Tenant-Id: $TENANT_ID" \  -H "Content-Type: application/json" \  -d '{    "name": "app-data",    "description": "Uploads and database files",    "poolName": "default",    "config": {}  }'

config is a map of string volume settings passed to the compute system as is. The response is 201 with the volume object, including its id and poolName. A name already in use returns 409. If the compute system refuses the volume (for example, an unknown pool), the request fails and nothing is saved.

Attach a volume to an instance

Add a disk device that points at the volume. In the dashboard, open the instance's Config tab and, under Instance devices, add a device:

• Name: for example data

• Type: disk

• Properties:

  inicopy

  pool=defaultsource=app-datapath=/mnt/data

source is the volume name and path is where it appears inside the instance.

With the API, send the device in a PATCH. The devices map replaces all of the instance's own devices, so include any you already have:

curl -X PATCH https://lahijan.example.com/api/v1/compute/instances/$INSTANCE_ID \  -H "Authorization: Bearer $LAHIJAN_TOKEN" \  -H "X-Tenant-Id: $TENANT_ID" \  -H "Content-Type: application/json" \  -d '{    "devices": {      "data": { "type": "disk", "pool": "default", "source": "app-data", "path": "/mnt/data" }    }  }'

To detach a volume, remove the device with the trash icon under Instance devices, or send the devices map without it. The volume and its data stay in the pool.

List, view and delete volumes

• GET /api/v1/compute/storage returns a page of volumes (limit, offset).
• GET /api/v1/compute/storage/{volumeId} returns one volume.
• DELETE /api/v1/compute/storage/{volumeId} deletes it and returns 204.

There is no update call.

Permissions

Creating a volume is checked against compute.network.create in this version, so only tenant admins and owners can create volumes with the default roles.