Managing an external storage system

You can manage the external storage-system resources that are exported to the system by using the system GUI or the system CLI. Managing the external storage system includes how to identify and change the system configuration of the external storage system resources.

Identifying an external storage system

To view the external storage-system serial-number in the management GUI, click Pools > External Storage. To identify the serial number, run the lscontroller command on CLI.

For Fibre Channel external storage systems, the serial numbers, the Fibre Channel worldwide node name (WWNN), or worldwide port name (WWPN) is displayed on the external storage system. The WWNN or WWPN can be used to identify the different external storage systems.

For iSCSI external storage systems, refer to the iscsi_port_id and ip fields in the output of lscontroller. Since the controller can have multiple Internet Protocol addresses (IP addresses), an iSCSI controller has multiple iscsi_port_id and ip listings. The ip field shows the IPv4 or IPv6 address for the iSCSI controller and is blank for other controllers. The iscsi_port_id refers to a row ID in the output of lsiscsistorageport command. The lsiscsistorageport iscsi_port_id lists the IQN of the target iSCSI controller in the target_iscsiname output field. Use the IP addresses and IQN gathered to determine the actual external storage system.

To verify the actual external storage system that has the IP addresses and IQN found:
  • Start the local user interface, or
  • Use the command-line tools that the external storage system provides.

Expanding the capacity of an external storage-system logical unit (LU)

On some external storage systems, you can expand the size of an LU by using vendor-specific disk-configuration software that is provided. The following steps are required for the system to use extra capacity that is provided in this way.

To ensure that the additional capacity is available to the system, follow these steps:
  • Remove the managed disk (MDisk) from the storage pool.
  • Wait for the migration to complete.
  • Verify the specified MDisk is listed as unmanaged by selecting Pools > MDisks by Pool and expand Unassigned MDisk to display all unmanaged Mdisks.
  • Use the vendor-specific, disk-configuration software to expand the size of the logical unit on the external storage system.
  • Instigate a system discovery to rescan the Fibre Channel network by following the Discovering an External Storage System procedure.
  • Wait for the discovery to complete.
  • Check the specified MDisk displays the additional capacity that was expanded.
  • Add the specified MDisk back to the pool.

The MDisk extra capacity becomes available for use by the system.

Changing the configuration of an existing external storage system

You can change the configuration of an existing external storage system when you want to delete and replace logical units (LUs).

To delete an existing external storage-system LU and replace it with a new LU:
  • Remove the specific existing MDisk from the storage pool by following the procedure to remove an external storage-system LU outlined in the topic Removing an external storage system.
  • Check the specified MDisk is no longer displayed in the Pools > External Storage view.
  • Use the vendor-specific, disk-configuration software to create a new LU and add the new LU mapping on the external storage system so that the new LU is now visible to the system.
  • Discover the newly exported external storage-system LU by following the procedure in Discovering an External Storage System.
  • Check the newly created MDisk is displayed in the Pools > External Storage view.
  • Add the newly created MDisk into a system pool.

The newly created MDisk capacity is now available for the system to use.

Important: When creating new external storage-system LU-mappings, always follow the system requirements as described in Planning an external storage system.

Modifying an external storage-system LU mapping

You can modify the LU mapping of an external storage-system LU. The LU mapping logical unit number (LUN) ID and LU unique identifier (UID) are linked and cannot be changed dynamically when the system is managing the MDisk.

To modify an LU-mapping LUN, complete the following steps:
  • Before removing an MDisk from a storage pool, make sure to preserve the existing LU array data on the external storage system.
  • Remove the specific existing MDisk from the storage pool by following the Removing an external storage system procedure to remove an external storage-system LU.
  • Check the specified MDisk is no longer displayed in the Pools > External Storage view.
  • Use the vendor-specific, disk-configuration software to add the new LU mapping on the external storage system so that the existing LU is now visible to the system through the new LU-mapping LUN.
  • Discover the newly exported external storage-system LU by following the procedure in Discovering an external storage system.
  • Check the newly re-created MDisk is displayed in the Pools > External Storage view correctly with the new LU-mapping LUN.
  • Add the newly re-created MDisk into a system pool.

The newly re-created MDisk with the changed LUN is now available for use by the system.

Important:

When creating a new external storage-system LU-mapping, always follow the system requirements as described in Planning an external storage system.

Servicing external storage systems

External storage systems that are supported for attachment to the system are designed with redundant components and access paths to enable concurrent maintenance. Hosts have continuous access to their data during component failure and replacement.