Migrating data from an IBM Spectrum Accelerate storage system
You can use an iSCSI attachment to migrate data from an external IBM Spectrum Accelerate™ system to a Storwize® V3700 system.
Before you begin
- Ensure that the iSCSI initiator and target system is running a level of software that can support iSCSI migration. For Storwize V3700 systems, software version 7.7.1 or later 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 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 Storwize V3700 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 source system and target dependent on availability of source ports with storage connectivity enabled.
For example, Figure 1 shows iSCSI connections between a Storwize V3700 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 systems 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
Configure the cabling and systems
- Connect the Ethernet cables from the ports on the Storwize V3700 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 Storwize V3700
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 Storwize V3700
system is
configured as a replication layer. To do so, enter the following lssystem
command.
svcinfo lssystem
- If the Storwize V3700
system is
not configured correctly, enter the following chsystem command.
svctask chsystem -layer replication
- If the Storwize V3700
system is
not configured correctly, enter the following chsystem command.
Establish the iSCSI connections
- On the Storwize V3700
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 lsportip
command.
svcinfo lsportip
- To display the IQN name, enter the lsnodecanister
command.
svcinfo lsnodecanister
- To display the IP address, enter the lsportip
command.
- On the Storwize V3700
system,
enter the following cfgportip command to configure one or more ports that can be
used for iSCSI attachment to the target storage system.
svctask cfgportip –node nodename -storage yes port_id
Note: If the ports are configured with IPv6 addresses, specify the -storage-6 parameter on the command. - On the IBM Spectrum Accelerate system, map the volume
that contains the data that you want to migrate to the Storwize V3700
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
- To use the IPv4 address of the iSCSI initiator system to map the volume, enter the following
command.
- On the Storwize V3700
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 Storwize V3700
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 Storwize V3700
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 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
- On the Storwize V3700
system,
complete the following steps to manage the logical unit.
- To create one empty storage pool, enter the mkmdiskgrp command. The extent_size is the size of the volume that you are migrating
from the iSCSI target system (as displayed in step 5).
The logical unit that is mapped from the iSCSI target system appears as an unmanaged-mode MDisk to the Storwize V3700 system.svctask mkmdiskgrp -ext extent_size
- To list the unmanaged-mode MDisks, enter the lsmdisk command.
svcinfo lsmdisk
- If the new unmanaged-mode MDisk is not listed, perform a fabric-level discovery. Enter the
detectmdisk command to scan the network for the unmanaged-mode MDisks.
svctask detectmdisk
- To convert the unmanaged-mode MDisk to an image mode volume disk, enter the
mkvdisk command.
svctask mkvdisk -vtype image -iogrp iogrp_name -mdiskgrp mdiskgrp_name -mdisk mdisk_name -mirrorwritepriority redundancy
- iogrp_name
- Name or ID of the I/O group.
- mdiskgrp_name
- Name or ID of the storage pool that you created in step 13.a.
- mdisk_name
- Name or ID of the unmanaged-mode MDisk.
- To list the hosts that were previously using the data that the MDisk now contains, enter the
lssasportcandidate command.
svcinfo lssasportcandidate
- If the host does not exist on the Storwize V3700
system,
enter the mkhost command to create a new iSCSI or Fibre Channel (or Fibre Channel
over Ethernet) host.
- To create a new iSCSI host, enter the following
command.
svctask mkhost -iscsiname host_iqn
- To create a new Fibre Channel or FCoE host, enter the following
command.
svctask mkhost -fcwwpn host_wwpn
- To create a new iSCSI host, enter the following
command.
- Enter the mkvdiskhostmap command to map the new volume to the host. When the
image mode volume is mapped, it becomes accessible for I/O operations to the host.
svctask mkvdiskhostmap -host hostname diskname
- To create one empty storage pool, enter the mkmdiskgrp command. The extent_size is the size of the volume that you are migrating
from the iSCSI target system (as displayed in step 5).
- Enter the lsmdiskgrp command to display information about the storage pools
that are visible to the Storwize V3700
system.
svcinfo lsmdiskgrp
- If no storage pools are available on the Storwize V3700
system to
migrate the storage pool that you created in step 13.a, 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
- If no storage pools are available on the Storwize V3700
system to
migrate the storage pool that you created in step 13.a, 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).
- Migrate the data from the iSCSI target IBM Spectrum Accelerate system to the storage pool on Storwize V3700
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 migrate data from the entire volume, enter the following migratevdisk
command.
- 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 Storwize V3700 iSCSI initiator system. Host I/O operations are also switched to the Storwize V3700 system.
What to do next
- On the Storwize V3700
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 Storwize V3700
iSCSI
initiator
system.
delete volume_name
- Disconnect the Ethernet cables that connect each system to the Ethernet switches.