Manage block devices
Block devices are logical storage volumes created in the storage cluster. A block device does not have any file systems and is similar to a logical storage volume created on an IP SAN or FC SAN.
A block device can be mounted to a host as a shared file system. The shared file system allows simultaneous access from multiple hosts. You can create files as VM disks on the shared file system.
A block device also can be mounted to a host through iSCSI and then mapped to a VM for use. The operating system can identify block devices, and use the devices after partitioning and formatting.
Attach a QoS policy to a block device as needed to limit the IOPS or bandwidth that the block device can use, preventing the block device from occupying too many resources.
Restrictions and guidelines
The total capacity of all block devices in a thick-provisioned disk pool cannot be higher than the available capacity of the disk pool.
The total capacity of all block devices in a thin-provisioned disk pool can be higher than the available capacity of the disk pool. However, over-allocation might cause service interruption, data loss, and even cluster crash.
If a data pool has been configured as an RBD storage pool, you cannot configure a block device in the data pool as a shared file system, template pool, or iSCSI LUN.
Deleting a block device deletes all data on the block device, and the deleted data cannot be restored. Before deleting a storage volume, make sure the storage volume is no longer needed.
When you expand a block device, the shared file system will also be expanded if the block device has been mounted as a shared file system.
Abnormal QoS policies cannot be attached to block devices.
You cannot move a block device to the recycle bin if that block device has been mapped to a client group.
Add a block device
On the top navigation bar, click Storage, and then select Block Device > Block Device Management from the navigation pane.
Select a cluster from the Cluster list in the upper right corner of the page if multiple clusters exist in the system.
Click Add.
Configure the parameters as described in "Parameters."
Click OK.
Edit a block device
On the top navigation bar, click Storage, and then select Block Device > Block Device Management from the navigation pane.
Select a cluster from the Cluster list in the upper right corner of the page if multiple clusters exist in the system.
Select a block device, and then click Edit.
Edit the parameters as described in "Parameters."
Click OK.
Expand a block device
Restrictions and guidelines
To expand a block device that has been mounted as a shared file system, make sure the following requirements are met:
A minimum of one host is using the shared file system.
All hosts that use the shared file system are in normal state and not enabled with maintenance mode.
The storage pool state is active on all hosts that use the shared file system.
The new capacity must be greater than the original capacity and cannot be greater than 64 TB.
Procedure
On the top navigation bar, click Storage, and then select Block Device > Block Device Management from the navigation pane.
Select a cluster from the Cluster list in the upper right corner of the page if multiple clusters exist in the system.
Click the
icon in the Actions column for a block device.
Enter the new capacity, and then click OK.
Delete a block device
On the top navigation bar, click Storage, and then select Block Device > Block Device Management from the navigation pane.
Select a cluster from the Cluster list in the upper right corner of the page if multiple clusters exist in the system.
Select a block device, and then click Delete.
Select a deletion mode as described in "Parameters."
In the dialog box that opens, click OK.
Mount a block device as a shared file system
On the top navigation bar, click Storage, and then select Block Device > Block Device Management from the navigation pane.
Select a cluster from the Cluster list in the upper right corner of the page if multiple clusters exist in the system.
Click the
icon for a block device.
Configure the parameters as described in "Parameters."
Click OK.
Attach a block device to a QoS policy
On the top navigation bar, click Storage, and then select Block Device > Block Device Management from the navigation pane.
Click the
icon in the Actions column for the target block device.
Select a QoS policy, and then click OK.
Detach a block device from its QoS policy
On the top navigation bar, click Storage, and then select Block Device > Block Device Management from the navigation pane.
Click the
icon in the Actions column for the target block device.
In the dialog box that opens, click OK.
View block devices using the specified disk pool
On the top navigation bar, click Storage, and then select Block Device > Block Device Management from the navigation pane.
Select a cluster from the Cluster list in the upper right corner of the page if multiple clusters exist in the system.
Select a disk pool on the top right of the page.
View block devices using the specified data pool
On the top navigation bar, click Storage, and then select Block Device > Block Device Management from the navigation pane.
Select a cluster from the Cluster list in the upper right corner of the page if multiple clusters exist in the system.
Select a data pool on the top right of the page.
Parameters
Add a block device:
Cluster: Cluster to which the block device belongs. This field is not configurable. You must select a cluster from the Cluster list in the upper right corner of the page before adding a block device. The Cluster list is available only when multiple clusters exist in the system.
Data Pool: Select a data pool for the block device.
Client Group: Select a client group to establish a mapping relationship between the block device and client group. Only clients in this group can discover the block device and use the storage resources provided by the block device.
Available Capacity: Available capacity of the data pool.
Capacity: Set the capacity of the block device.
If the disk pool of a block device uses the thin provisioning mode, the system allocates storage space to the block device on demand. The capacity of the block device can be larger than the available capacity of the data pool.
If the disk pool of a block device uses the thick provisioning mode, the system assigns a fixed amount of storage space to the block device. The capacity of the block device cannot be larger than the available capacity of the data pool.
Delete a block device:
Select a deletion mode:
Move to Recycle Bin: Move the block device to the block device recycle bin. Block devices in the recycle bin can be restored.
Permanently Delete: Permanently delete the block device with all data. This operation is not revocable.
Mount a shared file system:
Service Storage: Enable this option to allow the shared file system to be used for storing files of the VMs automatically deployed by the system. As a best practice, turn on this option.
NAA: Unique identifier of the block device.