Migrating data from an IBM Spectrum Accelerate storage system

Edit online

You can use an iSCSI attachment to migrate data from an external IBM Spectrum Accelerate system to a FlashSystem 7300 system.

Before you begin

Ensure that the iSCSI initiator system is running a level of software that can support iSCSI migration. At a minimum, software version 7.7.0 is required.
Ensure that the firmware that is installed on the iSCSI target storage system is at the level that is recommended by the manufacturer. Refer to the product documentation that is supplied with the storage system for information.
Verify that Ethernet ports are available and supported on each system.
- You can use any available Ethernet port to establish iSCSI connectivity between the system and the iSCSI target storage controller.
- To avoid performance bottlenecks, the iSCSI initiator and target systems must use Ethernet ports at the same speed. Do not use a combination of Ethernet links that run at different speeds.
Ensure that you have the appropriate number of Ethernet cables and switches to connect to the Ethernet ports on each system.
Ensure that the appropriate Ethernet ports on each system are connected to the appropriate Ethernet switches. For full redundancy and increased throughput, use two or more Ethernet switches. Similarly numbered Ethernet ports on each node of each system must be connected to the same switch. They must also be configured on the same subnet or VLAN.
IBM Spectrum Accelerate storage systems support horizontal scale-out capability, which means a single system can have 3 - 15 nodes as targets. However, all nodes have a single IQN that handles all connections. To provide fault tolerance, configure at least two target nodes to two or more source ports. More connections can be configured between a source system and target dependent on availability of source ports with storage connectivity enabled.

For example, Figure 1 shows iSCSI connections between a system (the iSCSI initiator) and an IBM Spectrum Accelerate system (the iSCSI target).

The graphic describes the connection between the system and an IBM Spectrum Accelerate external storage system. In this diagram, the system is composed of two I/O groups with two nodes. Each node has a maximum of four initiator ports with two configured through two switches to the target ports on the storage systems. The other two ports on each node are not configured. The first ports (orange) on each initiator and target node are connected through Ethernet switch 1. The second ports (blue) on each initiator and target node are connected through Ethernet switch 2. All target nodes on IBM Spectrum Accelerate storage systems use a single, common iSCSI target IQN and all volumes are accessible through all target nodes. Connectivity from the initiator system must be established to two or more target nodes. Available source ports on the system must be configured to connect to external storage. If a node is not enabled for external storage, ports on that node cannot be used as source ports for the connection. To enable a node for storage, select Settings > Network > Ethernet Ports. Right-click the port and select Modify Storage Ports to enable the port for iSCSI connections to storage systems.

Figure 1. Example of an iSCSI connection to an IBM Spectrum Accelerate (iSCSI target)

For information about configuring support for IBM Spectrum Accelerate systems, see Configuring IBM Spectrum Accelerate storage systems.

Procedure

In the following procedure, some steps are completed on the iSCSI initiator system and some steps are completed on the iSCSI target system.

Configure the cabling and systems

Connect the Ethernet cables from the ports on the system (iSCSI initiator) to the appropriate Ethernet switches. Use any available Ethernet port.
Connect the Ethernet cables from the ports on the IBM Spectrum Accelerate system (iSCSI target) to the appropriate Ethernet switches. Use any available Ethernet port.
Stop all host I/O operations.
On the IBM Spectrum Accelerate system, unmap the logical drives that contain the data to be migrated from the hosts.
On the IBM Spectrum Accelerate system, obtain the size of the volume that you want to migrate to the iSCSI initiator system. To do so, enter the following command, where volume_name is the name of the specific volume.
```
volume show volume_name 
```
Verify that the system is configured as a replication layer. To do so, enter the following lssystem command.
```
svcinfo lssystem
```
1. If the system is not configured correctly, enter the following chsystem command.
```
svctask chsystem -layer replication
```

Establish the iSCSI connections

On the iSCSI initiator system, enter the following commands to obtain the system's IP address or iSCSI qualified name (IQN).
- To display the IP address, enter the lsip command.
```
svcinfo lsip
```
On the system, enter the following mkip command to configure one or more ports that can be used for iSCSI attachment to the target storage system.
```
svctask mkip –node nodename -portset 3 -ip ipaddress -prefix prefix -port port_id
```
On the IBM Spectrum Accelerate system, map the volume that contains the data that you want to migrate to the system. To do so, enter one of the following commands.
- To use the IPv4 address of the iSCSI initiator system to map the volume, enter the following command.
```
select volume_name access create ipaddress ip_address
```
- To use the iSCSI qualified name (IQN) of the iSCSI initiator system to map the volume, enter the following command.
```
select volume_name access create initiator iqn_name
```
volume_name

Name of the volume from which you want to migrate data (see step 4).

ip_address

IPv4 address of the iSCSI initiator system, as displayed in step 7.

iqn_name

IQN of the iSCSI initiator system, as displayed in step 7.
On the system, enter the detectiscsistorageportcandidate command to discover the available ports on the iSCSI target system. The source_port_id is the Ethernet port on the iSCSI initiator system through which the discovery is made. The ipv4_addr is the IP address of the IBM Spectrum Accelerate system (iSCSI target).
```
svctask detectiscsistorageportcandidate –srcportid source_port_id -targetip ipv4_addr
```
Notes:
- If the ports on the iSCSI target system are configured with IPv6 addresses, specify the -targetip6 parameter on the command.
- The iSCSI target system might also require a user name and CHAP information to authenticate the request. Ensure that you specify the correct tgt_user_name and target_chap values on the command, as shown in the following example.
```
svctask detectiscsistorageportcandidate –srcportid source_port_id -targetip ipv4_addr -username tgt_user_name -chapsecret target_chap
```
Display information about the iSCSI ports that were discovered on the iSCSI initiator system. The lsiscsistorageportcandidate command returns information about the unique iSCSI Qualified Name (IQN) and Internet Protocol (IP) combination.
```
svcinfo lsiscsistorageportcandidate
```
Select one or more port candidates to configure by issuing the addiscsistorageport command. You can specify up to 64 candidate IDs, each separated by a colon. The candidate_id is the value in the ID column of the output that is displayed by the lsiscsistorageportcandidate command.
```
svctask addiscsistorageport candidate_id
```
Note: If you entered authentication information on the detectiscsistorageportcandidate command in step 10, you must also specify that information on this command. Ensure that you specify the correct tgt_user_name and target_chap values on the command, as shown in the following example.
```
svctask addiscsistorageport candidate_id -username tgt_user_name -chapsecret target_chap
```

Migrate the data

Display information about the iSCSI ports that were discovered on the iSCSI initiator system. The lsiscsistorageportcandidate command returns information about the unique iSCSI Qualified Name (IQN) and Internet Protocol (IP) combination.
```
svcinfo lsiscsistorageportcandidate
```
Enter the lsmdiskgrp command to display information about the storage pools that are visible to the system.
```
svcinfo lsmdiskgrp
```
1. If no storage pools are available on the system, enter the mkmdiskgrp command to create a new storage pool. The extent_size is the size of the volume that you are migrating from the iSCSI target system (as displayed in step 5).
```
svctask mkmdiskgrp -ext extent_size -name pool_name
```
Migrate the data from the iSCSI target IBM Spectrum Accelerate system to the storage pool on system. For information about migrating data to volumes, see Managing volumes.
- To migrate data from the entire volume, enter the following migratevdisk command.
```
svctask migratevdisk -mdiskgrp mdisk_group -vdisk vdisk_id
```
- To migrate data from selected extents, enter the migrateexts command.
```
svctask migrateexts -source mdisk_name -exts num_extents -target new_mdisk -threads 4 -vdisk vdisk_id
```
To monitor the progress of the data migration, enter the lsmigrate command.
```
svcinfo lsmigrate
```

Results

The data on the logical drives from the IBM Spectrum Accelerate system is migrated to the iSCSI initiator system. Host I/O operations are also switched to the system.

What to do next

On the system, enter the lsiscsistorageport command to display the configured ports on the iSCSI target system.
```
svcinfo lsiscsistorageport
```
Enter the rmiscsistorageport command to delete the configured iSCSI target ports. Specify the row number from the lsiscsistorageport output to identify the sessions to delete.
```
svctask rmiscsistorageport lsiscsistorageport_row_id
```
On the IBM Spectrum Accelerate system, enter the following command to delete the volume that you migrated to the iSCSI initiator system.
```
delete volume_name
```
Disconnect the Ethernet cables that connect each system to the Ethernet switches.