Configuring IBM Storwize and IBM FlashSystem external storage systems

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By default, IBM® Storwize® and IBM FlashSystem systems are configured as storage layer devices to the SAN Volume Controller replication layer.

Partnerships among the replication and storage layer systems are limited by these rules:
  • SAN Volume Controller is always in a replication layer and cannot be changed.
  • Storage layer systems can be used as external storage only by replication layer systems.
  • Replication layer systems can participate in Metro Mirror or Global Mirror partnerships only with other replication layer systems.
  • Storage layer systems can participate in Metro Mirror or Global Mirror partnerships only with other storage layer systems.
Note: If your storage controller is going to be used as virtualized storage behind SAN Volume Controller, it is assigned to the storage layer. Use the automatic configuration function in the management GUI for this configuration. If your storage controller is going to be used as a peer system for replication, it is assigned to the replication layer. The management GUI function cannot be used for the replication configuration.

Using the management GUI to configure IBM Storwize or IBM FlashSystem systems as external storage

Automatic configuration offers the ability to configure IBM FlashSystem or IBM Storwize systems as external storage with an existing SAN Volume Controller system. Automatic configuration implements optimal virtualization with a SAN Volume Controller system based on best practices. For these supported systems, the process can be completed in the management GUI during system setup or later as part of storage configuration.

The automatic configuration process is intended for new systems. If you want to virtualize this system with a SAN Volume Controller system, no other objects, such as volumes or pools, can be configured on the system.

The management GUI provides a guided process to ensure that these systems are configured correctly as external storage. This process is available during system setup of the IBM Storwize and IBM FlashSystem® systems that you plan to use as external storage or after system setup is completed. The automatic configuration process completes the following tasks automatically:
  • Provides prerequisite tasks that must be completed before you run the automatic configuration.
  • Creates RAID arrays based on the detected technology types of drives.
  • Creates a pool for each array.
  • Provisions capacity to pools based on best practices.
  • Maps all volumes to SAN Volume Controller as available MDisks.
The following restrictions apply to running this process:
  • If you run the process after system setup is complete, no configuration objects such as pools, volumes, or hosts can be configured on the system. To use a system for external storage, these objects must be removed. This process is disruptive and data can be lost.
  • Only Fibre Channel connections are supported between SAN Volume Controller and the IBM Storwize or IBM FlashSystem storage system that is used as external storage.
  • SAN zoning for SAN Volume Controller and these systems must be complete.

On the Automatic Configuration for Virtualization page of the system setup wizard for these products, select On to start the process and click Next. If you already completed system setup for the system, you can also select Settings > System > Automatic Configuration.

If you are using compression, encryption, or data reduction pools on your SAN Volume Controller, you cannot overprovision usable storage on the system that is being virtualized.

To prevent overprovisioning on the system that is being virtualized, the automatic configuration process reserves capacity in specialized volumes that are named RESERVED_SPACE_do_not_use_or_delete_X, where X is an integer. These extra volumes create a portion of the effective capacity and cannot be used for I/O operations to ensure performance. If these volumes are deleted, arrays can become overprovisioned and I/O operations can be affected.

Before the wizard completes automatic configuration, you are prompted to complete the following prerequisite tasks:
Add enclosures
If you have any control or expansion enclosures to include as part of the external storage to be virtualized, you can select to add them. If you do not have more enclosures to add, this part of the prerequisite steps can be skipped. If you do have enclosures to add, but they are not automatically detected by the management GUI, verify the cabling between the system and the enclosures. For more information, see the installation information that came with the system.
Verify zoning on the SAN Volume Controller system
In Fibre Channel connections, zoning is the process of grouping multiple ports to form a virtual, private, storage network. Ports that are members of a zone can communicate with each other, but are isolated from ports in other zones. Before automatic configuration can be completed, verify that the SAN Volume Controller is zoned correctly as part of its storage area network (SAN) configuration.
Define a host cluster to represent the SAN Volume Controller
As part of the prerequisite steps, you need to create a host cluster that represents the SAN Volume Controller system. Creating a host cluster simplifies the port management between the SAN Volume Controller and the systems that are virtualized as part of the automatic configuration. In the host cluster that represents the SAN Volume Controller, a host represents a node, and each host port represents a port on a node. The management GUI displays worldwide port names (WWPNs) that are associated with node ports.
After these prerequisite steps are completed, the automatic configuration process begins. During this process the following actions are completed automatically:
  • Formats drives. Drives remain offline until formatting completes. Do not proceed with procedure until all drives are formatted.
  • Creates the appropriate RAID arrays based on technology type of the drives.
  • Creates a pool for each array.
  • Provisions all usable capacity in each pool to volumes based on best practices.
  • Maps all volumes to the SAN Volume Controller system for virtualization as MDisks.

After the process finishes, you are prompted to complete tasks on the SAN Volume Controller system to begin using this system as external storage.

Completing the management GUI configuration on the SAN Volume Controller system

After the automatic configuration process completes, you need to access the system and complete the configuration so you can use the storage.

The automatic configuration process creates a list of volumes that can be assigned as the MDisks for pools that are configured on the system. After the automatic configuration process completes, export the volume information to help you configure these objects.

For systems that support compressing arrays, the automatic configuration process uses specialized volumes that are named RESERVED_SPACE_do_not_use_or_delete_X, where X is an integer. These extra volumes create a portion of the effective capacity that cannot be used for I/O operations to ensure performance. If these volumes are deleted, arrays can become overprovisioned and I/O operations can be affected. They must not be mapped to the system and are created for preventing a storage administrator from accidentally provisioning more volumes from these pools. You can edit and rename them for your system.

To finish the configuration on the SAN Volume Controller system, complete the following steps:
  1. In the management GUI, select Pools > MDisks by Pools.
  2. Select Actions > Discover Storage.
  3. Verify that the discovered MDisks correspond with the exported volumes that were generated during the automatic configuration process. The available MDisks display at the bottom of the MDisks by Pools. Click Assign.
  4. On the Assign Storage page, select the name of the pool that you want to add the storage to. Click Assign. If your system supports self-compressing arrays and you want to use data reduction pools, all volumes that use that pool must be configured with compression enabled.
  5. After you assign storage to pools, you can create volumes, map hosts, and configure other advanced functions on the SAN Volume Controller system.

Tasks to configure the storage layer system

To configure a system as a storage layer, follow these general tasks:
  1. On the storage layer system, first define a host object and add all worldwide port names (WWPNs) from the SAN Volume Controller system to it.
  2. On the storage layer system, create host mappings between each volume that you want to manage by using SAN Volume Controller and the host object that you created.
The volumes that are presented by the storage layer system appear in the SAN Volume Controller managed disk (MDisk) view. The storage layer system appears in the SAN Volume Controller view with a vendor ID of IBM.

Quorum disks on storage layer storage systems

The storage layer systems support quorum disks. Clustered systems that have a storage level system can choose MDisks that are presented by a storage level system as quorum disks.

Advanced functions for storage layer systems

Replication layer systems can use storage that is presented by the storage layer system, but Metro Mirror and Global Mirror cannot interoperate between the two systems. Replication layer systems can participate in Metro Mirror and Global Mirror partnerships only with other replication layer systems. Storage layer systems can participate in Metro Mirror and Global Mirror partnerships only with other storage layers.

For more information, see Metro Mirror and Global Mirror partnerships information.

Volumes that are defined on a storage layer system can be used by the replication layer system as a source or target for advanced copy functions. Advanced copy functions include FlashCopy®, Metro Mirror, and Global Mirror. IBM Storwize and IBM FlashSystem advanced copy functions are not supported for volumes that are used as MDisks.

Sharing the storage layer system between a host and the system

An IBM Storwize or IBM FlashSystem storage system can present some volumes to the SAN Volume Controller system and other volumes to hosts on the SAN. However, an individual volume cannot be presented to both the SAN Volume Controller system and a host simultaneously.

SAN zoning for storage layer systems

If many storage layer systems are managed by a single SAN Volume Controller system, be aware of the published limit for maximum IBM Storwize or IBM FlashSystem storage systems per fabric. If the limit is exceeded by as little as a single storage system, divide the storage layer systems into multiple zones. Replication layer IBM Storwize or IBM FlashSystem systems count toward the maximum number of SAN Volume Controller nodes that might be present within a single SAN zone. For more information, see the following website:

http://www.ibm.com/support