How to create, read, and delete VDC volumes

When to use this procedure

When a VDC needs a block volume: for application data, for a shared disk for a host outside the cluster, or for future export over iSCSI. A volume is created inside VDC storage that is already enabled, counts against its quota, and is not visible to anyone until it is mapped.

This procedure covers the entire volume lifecycle: creation, reading parameters and used space, and deletion. Mapping a volume to an initiator is a separate step, described in "Connecting volumes over iSCSI". If VDC storage is not yet enabled, start with creating a VDC with Unified Storage.

Prerequisites

• The Unified Storage feature is enabled in the cluster options.
• VDC storage is enabled — the Storage tab of the VDC card shows its summary rather than a prompt to enable it.
• The Create vDC Volume privilege for creation and Delete vDC Volume for deletion — both are available to the Cluster master role and to a VDC administrator within their VDC.
• vStack Center version — 3.0.4.

Step 1. Check the available quota

Storage capacity equals the VDC's storage quota; the storage has no separate limit. Before creating a large volume, check how much of the quota is already used.

1. Open Virtual Data Centers.
2. Look at the Storage column: it shows used space and the current quota, with a small indicator alongside. If no quota is set, the second value is "∞".
3. The filter next to the search field filters VDCs by storage state: All storage states, Storage enabled, Storage disabled.

The quota covers all space used by the VDC, not just storage volumes: virtual machine disks are added together with volumes. The limit is edited in the VDC settings using the Storage (GB) field.

Step 2. Create a volume

1. Open the VDC card → Storage tab → Volumes subtab.
2. Click Create volume.
3. Complete the form:

Field	What to specify
Volume name	1–63 characters: lowercase Latin letters, digits, periods, and hyphens; the first and last characters must be a letter or digit; the name must be unique within this VDC's storage
Size	Volume size, at least 1 GB; select the unit next to the number
Protocol	iSCSI if the volume is to be mapped immediately, or Choose later
LUN ID	The number under which the volume is visible on the target; the field is preset to an available number
Initiator Group	An existing group, a new group, or Assign later

4. Click Create.

The pool is not selected in the form — it is taken from the VDC storage. The form does not ask for the block size either: the platform supplies the default value of 32768 bytes, which appears in the Block size column of the volume list.

Capacity is reserved against the quota before contacting the pool controller. If the controller rejects the operation, the reservation is released and no volume remains on the pool or in the list.

Step 3. View the VDC volume list

The Volumes subtab shows this VDC's volumes in a flat table.

Column	What it shows
ID	Volume identifier; a link to the volume page
Name	Volume name in the storage; also a link
Size	Volume size
Block size	Block size supplied at creation
Protocol	Export protocol, or None if the volume is not mapped
Access	The initiator group to which the volume is exported
Status	Mapped or Unmapped

The table supports search, sorting by column, and pagination. Empty storage shows the message "No volumes yet".

Volumes are visible even before iSCSI is configured: creating a volume and mapping it are independent steps. A separate "All volumes" screen consolidates volumes from all VDCs: a single paginated table with filters for VDC, pool, mapping status, and protocol. Each row shows the VDC, pool, and volume size. The screen is available only to the Cluster master role. An empty filtered result is distinguishable from a cluster with no volumes.

Step 4. Open the volume card

Click the volume name or identifier in the list.

The page header shows the volume name and its status: Mapped or Unmapped. Below are two cards and a mapping section.

Block	Contents
Properties	Name, Pool, Size, Path — the volume's full name on the pool. A mapped volume also has Protocol, LUN ID, and Target, with a link to the target page
Capacity	Used and available space, compression and deduplication ratios. Available space is the space remaining in the volume itself, not the pool's free capacity
Initiator Group Mapping	The initiator group name with a link to its page, and the Initiators and Authorized networks subcards

Read the page as follows. vStack Center supplies Properties and mapping status from its records, while Capacity metrics are requested from the pool controller when the page opens. An unavailable controller does not prevent the page from loading: Capacity values are empty, and everything else is displayed.

For an unmapped volume, the Initiator Group Mapping section shows "Volume is not mapped" and the Map volume button, while Protocol in Properties is None.

The indicator for each initiator in the Initiators subcard reflects a comparison of group membership with the controller, not session state. Connected means the controller knows this entry; Disconnected means the entry exists only in vStack Center records. If the controller is unavailable, there is nothing to compare against, and the indicator is empty.

Step 5. Delete the volume

Deletion is initiated with the Delete volume action. If the volume is mapped, vStack Center first removes the mapping, then deletes the volume.

Once the controller confirms, the volume disappears from the list and the VDC quota is released. If the controller reports that it has no such volume, the operation is also considered successful — the records are cleared and the discrepancy is resolved.

If the mapping was removed successfully but the controller then rejected volume destruction (for example, because of snapshots or clones), the volume remains in the list without a mapping. Remove the dependency and retry deletion; to restore access to the volume, map it again.

Verify the result

Return to the Volumes subtab.

Expected after step 2: the table contains a row with your volume name, the Size column shows the specified size, and the Status column shows Unmapped. Expected after step 5: the table no longer contains a row for this volume, and used space in the Storage column on the Virtual Data Centers screen has decreased by the volume size.

Troubleshooting

What you see	Why	What to do
"Storage is not enabled for VDC" (-45013)	VDC storage is not enabled, so there is nowhere to create volumes	Enable storage on the Storage tab — see the steps in creating a VDC with Unified Storage
"Quota exceeded" (-45017)	The requested size exceeds the VDC's available quota; the message shows the requested and available space	Reduce Size or increase the Storage (GB) quota in the VDC settings
"Volume already exists" (-45018)	The name is used by another volume in the same storage	Specify a different Volume name; find the volume using that name in the Volumes list — names are unique within VDC storage, not the cluster
"Invalid volume parameters" (-45019)	Values failed validation: size, block size, or name format	Check Volume name against the rules in step 2 and ensure Size is at least 1 GB
"Unknown volume" (-45026)	The volume does not exist, belongs to another VDC, or has not yet been confirmed by the controller	Refresh the Volumes list and open the volume again; the same response covers all three cases — ownership of another VDC's volume is not disclosed
"Unified Storage feature is disabled" (-45001)	The Unified Storage feature is disabled in the cluster options	The cluster administrator must enable it; while the feature is disabled, storage operations are rejected, with no exception for the Cluster master role
Storage pool not found (-45002)	The records and pool state are inconsistent	Check the pool state in the "Storage pools" section
The pool controller did not respond or rejected the operation (-45020, -45021)	The pool is unavailable or rejected one of the deletion steps	Check pool availability, refresh the volume card, and check the mapping status before retrying
Deletion rejected with a message from the platform	Snapshots or clones depend on the volume — the platform passes the reason through unchanged	Remove the dependencies on the pool and retry deletion
"Access denied" (-403)	A required privilege is missing, or the VDC is outside your scope	Work within your VDC; reads across VDCs are available only to the Cluster master role

See also

• VDC storage — model and architecture — model invariants and access separation.
• Connecting volumes over iSCSI — how to export a volume to an initiator and remove the mapping.
• How to view and change dataset properties — ZFS properties at the dataset level.

API methods

API operations covered on this page: vdc-create-volume, vdc-list-volumes, vdc-volume-get, vdc-volume-delete, vdc-storage-list, cluster-list-volumes — see the API reference.