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This chapter describes how to use DMM CLI commands to configure and monitor data migration jobs.
The DMM feature includes CLI commands to configure and perform data migration jobs. Job and session configuration commands are entered at the switch CLI prompt.
A DMM job can be active on more than one switch. For example, in a dual-fabric topology with multipath configurations, the DMM job runs on a switch in each fabric. To configure the job, you enter DMM CLI commands on both switches.
The DMM feature runs on an MSM-18/4 module, MDS 9222i switch or MDS 9250i switch. Each session runs on only one MSM-18/4 module, MDS 9222i switch or MDS 9250i switch. Enter the session configuration commands on the MDS switch that will perform the session migration.
The DMM show commands are accessed directly from the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch. From the command prompt in the switch, you must attach to the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch before entering these commands.
When using the DMM CLI commands, note the following guidelines:
When creating a server-based migration job, you must include all possible paths from the server HBA ports to the LUNs being migrated because all writes to a migrated LUN need to be mirrored to the new storage until the cutover occurs, so that no data writes are lost.
For additional information about selecting ports for server-based jobs, see the “Ports in a Server-Based Job” section.
When you enter the command to create a data migration job, the CLI enters DMM job configuration submode. This submode provides commands to configure the server HBA ports, storage ports, and job attributes. The job is only created on the MSM-18/4 module, MDS 9222i switch or the MDS 9250i switch when you enter the commit command.
In a dual-fabric topology with redundant paths, the data migration job runs on an MSM-18/4 module, MDS 9222i switch or the MDS 9250i switch in each fabric. You need to configure the job on both MSM-18/4 modules or MDS 9222i switches.
In this chapter, the examples and command descriptions use the following terminology (Figure 6-1):
The steps to configure a data migration job are described in the following sections:
Note This step is not required for a server-based data migration job.
Prior to creating a storage-based data migration job, you must retrieve the virtual initiator (VI) port world wide name (PWWN) and create a new zone containing the PWWNs of the VI and the storage ports. To use the new zone, add the new zone to a zone set and activate the zone set.
To configure the VI in Fabric 1, follow these steps:
Prior to creating the data migration job, you must complete the following configuration tasks on the storage devices:
1. Configure the existing storage to give the VI PWWN access to LUNs that need to be migrated.
2. Configure the new storage to give the VI PWWN access to LUNs that need to be migrated.
Note For a dual-fabric topology, you must repeat the same set of configuration steps on switch B. Retrieve the VI information and create a new zone on switch B and configure the storage to allow the VI to access the LUNs exposed in fabric B. For an example configuration, see the “Storage-Based Migration Example” section.
To configure a data migration job, first create the job on Switch A. After creating the job, the CLI enters DMM job configuration mode, where you enter the commands for configuring the job.
To create the data migration job, follow these steps:
Use the commands in DMM job configuration mode to add the server and storage ports to the job.
Note To prevent data corruption, the job must contain all the server HBA ports that can access the set of LUNs being migrated, and all storage ports that expose these LUNs:
For additional information, see the “Checking the Storage ASL Status” section.
In a dual-fabric topology, configure the IP address of the peer MSM-18/4 module, MDS 9222i switch or MDS 9250i switch (the DMM peers communicate using the management IP network).
To configure the data migration job, use the following steps:
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Specifies the VSAN and PWWN of the server HBA port to include in the migration. Note All server HBA ports (in fabric 1) that can access the LUNs to be migrated need to be added to this job. |
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switchA(config-dmm-job)# storage vsan 1-4093 pwwn pWWN existing |
Specifies the VSAN and PWWN of the existing storage port. Note All existing storage ports (in fabric 1) that expose the LUNs to be migrated need to be added to this job. |
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Specifies the VSAN and PWWN of the new storage port. Note All new storage ports (in fabric 1) that expose the new LUNs need to be added to this job. |
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switchA(config-dmm-job)# attributes job_type { 1 | 2 } job_mode { 1 | 2 } job_rate { 1 | 2 | 3 | 4 } job_method { 1 | 2|3 } |
Specifies the job type, job mode, and job rate: For job_type, enter 1 for server-based migration or 2 for storage-based migration. For job_mode, enter 1 for online or 2 for offline migration. For job_rate, enter 1 for best effort, 2 for slow, 3 for medium, and 4 for fast data migration. For job_method, enter 1 for Method 1, 2 for Method 2. For additional information about data migration rate, see the “Configuring Migration Rate” section. |
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Configures the IP address of the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch on switch B. For information about configuring the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch IP addresses, see the “Configuring IP Connectivity” section |
The next step is to commit the data migration job on switch A. To commit the job, use the commit command.
When you enter the commit command, the switch sends the job configuration to the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch.
The DMM feature sends configuration information to other switches in the fabric as required, so that all traffic between the server HBA port and the existing storage is redirected to the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch.
The MSM-18/4 module, MDS 9222i switch or MDS 9250i switch performs discovery of all existing and new storage LUNs visible to the server HBA ports/VIs in this job.
Note The commit command may require a noticeable amount of time to complete, depending on the number of LUNs to be discovered.
The next step is to configure the data migration job on the peer MSM-18/4 module, MDS 9222i switch or MDS 9250i switch.
Note You must use the same job number that you created on switch A.
To configure the data migration job on the peer MSM-18/4 module, MDS 9222i switch or MDS 9250i switch, follow these steps:
The next step is to configure sessions in the data migration job. For a server-based migration, configure all of the sessions on one MSM-18/4 module, MDS 9222i switch or MDS 9250i switch.
For a storage-based migration, you can manually balance the load on the MSM-18/4 modules or the MDS 9222i switches by configuring sessions on both the MSM-18/4 modules or the MDS 9222i switches.
Note For a storage-based migration, use the PWWN of the VI as the server in the session configuration.
To verify that the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch has discovered the LUNs correctly, enter the show dmm job job-id job id storage command from the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch CLI.
To configure sessions, follow these steps:
The topology (Figure 6-2), is dual fabric with multipath ports defined in the server and redundant paths to the storage devices.
Figure 6-2 Topology for the Example
On both switches, the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch is located in slot 8. The PWWNs for the ports are listed here:
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The following example shows how to configure a data migration job on switch A:
The following example shows how to configure a data migration job on switch B:
The following example shows how to configure data migration sessions on switch A:
The following example shows how to start a data migration job on switch A:
The topology (Figure 6-3), is dual fabric with multipath ports defined in the server and redundant paths to the storage devices.
Figure 6-3 Storage-Based Migration Example
On both switches, the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch is located in slot 8. The PWWNs for the ports are listed here:
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The following example shows how to configure the VI on switch A:
The following example shows how to configure the zone and zone set on switch A:
The following example shows how to configure the data migration job on switch A:
The following example shows how to configure the VI on switch B:
The following example shows how to configure the zone and zone set on switch B:
The following example shows how to configure the data migration job on switch B:
The following example shows how to configure the data migration sessions on switch A:
The following example shows how to start the data migration job on switch A:
The following example shows how to configure the data migration sessions on switch B:
The following example shows how to start the data migration job on switch B:
The DMM CLI provides a set of commands to control jobs that have been configured. The job state determines which commands are valid to run. Table 6-1 shows job state values.
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The job has been configured with a scheduled start time. It will automatically start at that time. |
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The job has been stopped because of failures. See Table 5-5 for details. |
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The job has been reinitialized because of failures. See Table 5-6 for details. |
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Table 6-2 describes the data migration commands.
Note You must enter these commands on the switch with sessions configured. If both the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch have sessions configured, enter the commands on both switches.
To control the data migration job, follow these steps:
Use the show dmm job command in the MSM-18/4 module, MDS 9222i switch or MDS 9250i switch CLI to monitor the status of data migration jobs, and the current progress of jobs and sessions that are in progress.
To monitor data migration jobs, follow these steps:
For additional information about monitoring and troubleshooting data migration jobs, see Chapter5, “Troubleshooting Cisco MDS DMM”
When all of the sessions in a job have completed successfully, you can delete the job in coordination with other post-migration tasks, which are described in the following sections:
When all of the sessions in a job have completed successfully, you can optionally perform verification of the data in the new storage location. The MSM-18/4 module, MDS 9222i switch or MDS 9250i switch compares the data in the new storage with the data in the existing storage by reading each migration region from the existing and new storage, and then performing a comparison of the data.
Note Verification is performed in off line mode. Any service using the existing storage needs to be quiesced before you start verification.
After the data migration job has completed successfully, you need to reconfigure the server to use the new storage. The exact post-migration configuration steps vary depending on the operating system of the server.
To reconfigure the server, you might need to take the following steps:
– For Method 1— Delete the data migration job. DMM removes the FC-Redirect entries to the SMM. Server writes are no longer mirrored to the existing and new storage.
– For Method 2— Finish the data migration job. When the job moves to Completed state, delete the data migration job.
– Configure zoning to remove server access to the existing LUNs.
– Use an appropriate array tool to remove the masking or mapping access. Choose this option if an application that is being migrated requires access to the existing storage after the first migration is completed.
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Finishes the specified data migration job. This is valid only for Method 2. |
When job is in the Failed state, you can restart the job using the start command. This command will start the job from point of last failure.
The job should be in Failed state to restart the failed session.
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When the sessions in a job have failed, you can restart them using the restart_session command. This command restarts all the failed sessions in the job.
To restarts all the failed sessions in the job, follow this step:
The job should be in InProgress state to restart the failed sessions.
The command is only available for the job which in currently doing migration (Job in InProgress state).
Note The failed sessions can now be restarted when the DMM job is still in IN_PROGRESS state.
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switch(config)# dmm module module-id job job-id restart_session |
To delete the data migration job, follow this step:
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