Migrating data from a Storwize V3500 or Storwize V3700 system

You can use SAS connections to migrate data from a Storwize® V3500 or Storwize V3700 system to a Storwize V5000 Gen2 system.

Before you begin

Install and configure the system.
Ensure that the Storwize V3500 or Storwize V3700 system is running a level of software that can support SAS migration (minimum version 7.6.1.0).
Verify that the host attachment ports are available.
Storwize V5030 and Storwize Storwize V5030F systems support 12 Gbps SAS host attachment I/O but must have the optional host interface adapter installed.
Ensure that you have four mini SAS cables.
Stop all host I/O operations.
Unmap the logical drives that contain the data from the hosts.
Verify that the Storwize V5000 Gen2 system is configured as a replication layer system. To do so, enter the following command.
```
svcinfo lssystem
```
If the Storwize V5000 Gen2 system is not configured as a replication layer system, enter the following command.
```
svctask chsystem -layer replication
```
Verify that the Storwize V3500 or Storwize V3700 system is configured as a storage layer system. To do so, enter the following command.
```
svcinfo lssystem
```
If the Storwize V3500 or Storwize V3700 system is not configured as a storage layer system, enter the following command.
```
svctask chsystem -layer storage
```

Procedure

Hardware configuration

Unplug the SAS cables between the Storwize V3500 or Storwize V3700 system and the hosts.
Ensure that no SAS host ports on the Storwize V5000 Gen2 system are occupied.
Connect four SAS host ports on the Storwize V3500 or Storwize V3700 system to the SAS host ports on the Storwize V5000 Gen2 system. Connect each Storwize V5000 node to each Storwize V3500 or Storwize V3700 node canister..

You can use SAS ports 1, 2, and 3 on the Storwize V3500 or Storwize V3700 system. Do not use SAS port 4.

Note: 12 Gbps SAS cables have a square design rather than a rectangular design, which makes them easy to insert upside down. You can identify the correct orientation by observing the ridge at the top of the SAS connector and lining it up with the ridge on the node canister. However, this ridge is not enough to prevent the cable from being inserted incorrectly. Take extra care as the orientation of the SAS ports on a connector for a host interface adapter is the opposite of the onboard SAS ports.

The cabling for the port connections varies for each Storwize V5000 Gen2 system. The following figures show examples of the connection between a Storwize V3500 or Storwize V3700 system and a Storwize V5000 Gen2 system. To provide extra redundancy and ensure that the detected MDisks are not degraded, ensure that each controller is connected to both node canisters on the Storwize V5000 Gen2 system.

Figure 1 shows the cabling between a Storwize V3500 or Storwize V3700 and a Storwize V5030 system. The Storwize V5030 system has a 12 Gbps SAS host interface adapter installed. Any 2 ports on the host interface adapter can be used. In this example, port 1 and port 2 are used.
Figure 1. Connecting SAS cables from a Storwize V3500 or Storwize V3700 system to a Storwize V5030 system
Connect the remaining Storwize V5000 Gen2 SAS host ports to the host server SAS ports.

Software configuration

To get the SAS worldwide port name (WWPN) of the Storwize V5000 Gen2 system, enter the following command on the Storwize V3500 or Storwize V3700 system.
```
svcinfo lssasportcandidate
```
On the Storwize V3500 or Storwize V3700 system, define a new host using the SAS WWPNs that were detected from the Storwize V5000 Gen2 system in step 4.
Enter the following command, where sas_wwpn is a colon-separated list of SAS WWPNs of the Storwize V5000 Gen2 system. If you are using the management GUI, set the Host type (operating system) to Generic.
```
svctask mkhost -saswwpn sas_wwpn
```
On the Storwize V3500 or Storwize V3700 system, map the logical drives to the newly-created host as a logical unit.
- To select and map several drives at one time, use the management GUI.
- To map an individual drive, enter the following command.
```
svctask mkvdiskhostmap -host hostname diskname
```
  hostname
  
  Name or ID of the SAS host created in step 5.
  
  diskname
  
  Name or ID of the volume that you want to migrate to the Storwize V5000 Gen2 system.
On the Storwize V5000 Gen2 system, complete the following steps to manage the logical unit.
1. To create one empty storage pool, enter the following command.
```
svctask mkmdiskgrp -ext extent_size
```
  The logical unit mapped from the Storwize V3500 or Storwize V3700 system appears as an unmanaged-mode MDisk to the Storwize V5000 Gen2 system.
2. To list the unmanaged-mode MDisks, enter the following command.
```
svcinfo lsmdisk
```
3. If the new unmanaged-mode MDisk is not listed, perform a fabric-level discovery.
  Enter the following command to scan the network for the unmanaged-mode MDisks.
```
svctask detectmdisk
```
4. To convert the unmanaged-mode MDisk to an image mode volume disk, enter the following command.
```
svctask mkvdisk -vtype image -iogrp iogrp_name -mdiskgrp -mdisk mdiskgrp_name 
 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 7.a.
  
  mdisk_name
  
  Name or ID of the unmanaged-mode MDisk.
5. To list the SAS WWPN of hosts that were previously using the data that the MDisk now contains, enter the following command.
```
svcinfo lssasportcandidate
```
6. If the SAS host does not exist on the system, enter the following command, where sas_wwpn is the colon-separated list of SAS WWPNs of the host server.
```
svctask mkhost -saswwpn sas_wwpn
```
7. Map the new volume to the SAS hosts.
  Enter the following command to create a new mapping between a volume and a host. The image mode volume becomes accessible for I/O operations to the host.
```
svctask mkvdiskhostmap -host hostname diskname
```
  hostname
  
  Name or ID of the SAS host you created in step 7.f.
  
  diskname
  
  Name or ID of the volume you created in step 7.d.
On the host server, you can detect the new volume presented from the Storwize V5000 Gen2 system and start I/O operations towards it.
If you have more than one logical drive to migrate, repeat steps 6 through 8.
On the Storwize V5000 Gen2 system, complete the following steps to start migration for each image-mode volume. For more information about migrating data to volumes, see Managing volumes.
1. To create one empty internal storage pool, enter the following command.
```
svctask mkmdiskgrp -ext  extent_size
```
2. To create arrays with internal drives and add them to the internal storage pool, enter the following command.
```
svctask mkarray -level raidtype -drive drivelist mdiskgrpname
```
  raidtype
  
  Type of RAID array to be created.
  
  drivelist
  
  List of drive IDs.
  
  mdiskgrpname
  
  Name or ID of storage pool created in step 7.d.
3. After you determine the volume that you want to migrate and the new storage pool that you want to migrate it to, enter the following command.
```
svctask addvdiskcopy -mdiskgrp newmdiskgrname vdiskname
```
  The copy ID of the new copy is returned. The copies are now synchronized such that the data is stored in both storage pools.
4. To check the progress of the synchronization, enter the following command.
```
svcinfo lsvdisksyncprogress
```
5. After the volume reports that it is fully synchronized and you are ready to stop using the external storage system, enter the following command on the image-mode copy of the volume.
```
svctask rmvdiskcopy
```
  The image-mode copy is deleted, and its associated MDisk becomes unmanaged.

Results

The data on the logical drives from the Storwize V3500 or Storwize V3700 system is migrated to the Storwize V5000 Gen2 system. Host I/O is also switched to the Storwize V5000 Gen2 system.

What to do next

You can now disconnect the SAS cabling between the Storwize V3500 or Storwize V3700 system and the Storwize V5000 Gen2 system.