Replacing an Array

This help page provides information to guide you through the procedures to replace a failed array with a new one. It contains the following topics:

Overview   (back to top)

Array migration is the process of relocating user data and system information from the drives of a source array such as a Hitachi Simple Modular Storage 100 system to the drives of an identical target array. Array migration is normally used when a failure occurs in an array and requires the array to be replaced.  It is achieved using proprietary cables or LAN cables supplied with the target array and use the data migration capabilities of Navigator 2. When the original array set single controller and the new array set dual controller, you can update to new array from old array, and can expand HDD number and HDD capacity.

Once the migration operation is completed, all the disks that were available on the source array will be available on the target array. At that time,  I/O requests can be redirected to the target.

If you used Hitachi Adaptable Modular Storage ShadowImage or Copy-on-Write SnapShot to create primary volume/secondary volume (P-Vol/S-Vol) pairs on the source, however, the structure will migrate to the target, but the relationship between the pairs will not. Instead, the devices will appear as simplex (SMPL), and you will have to recreate the device relationships and snap shots on the target. During the data migration operation, hosts and applications can continue to send input/output (I/O) requests to the source. However, performance will be degraded.

The duration of the migration operation depends on drive capacity. Migrating 4.5 TB of data, for example, can take approximately 24 hours. Therefore, you may want to perform the data migration when the Simple Modular Storage is least likely to be accessed, such as over a weekend or holiday.

Primary Tasks

The procedure to replace an array includes the following primary tasks:

 

Task

Description

Check for New Array

Check for New Array is a function to verify that an array can be designated as the destination array in the array migration procedure. You acknowledge that user data and system information of the array can be overwritten by releasing the Migration Guard.

Auto Migration

Array Migration is a function that copies user data and system information from one array to another and then uses he second array instead of the first.

Completing the auto migration process

Completing the auto migration process includes two steps:

  • Setting the Target Array to Normal Operation

  • Shredding the data on the source array

Data Shredding

 

Data Shredding is a function to erase user data and system information in an array after a successful Array Migration and before it is sent back to the reseller.

Resetting (releasing) the Migration Status

Reset Migration Status is a function that resets the migration status of a source array. You acknowledge that you can re-execute an auto migration process by "releasing" the Migration Status.

Check for New Array   (back to top)

If you have previously used the array that you are going to use to replace a failed array, you need to specifically acknowledge that you will be overwriting the array by releasing the Migration Guard. This is because the Migration Guard protects data from being overwritten by the copy feature of Array Migration.

Release Migration Guard   (back to top)

  1. Go to Settings > Replacement of Array and select Check for New Array.

  2. Release Migration Guard is enabled if the Migration Guard shows Guarded, meaning that the data has ben written on the array since the guard was last released. The guard is released initially. Click Release Migration Guard in the Migration Guard Setting if you acknowledge that the array can be overwritten.

  3. A confirmation dialog box is displayed. Click the and then click OK to continue.

Auto Migration   (back to top)

Array Migration is a function that copies user data and system information from one array to another. When a failure that requires the entire array to be replaced occurs in an array, you can migrate data in the source array with failure to a new array in a simple way with Array Migration. One or two migration cables that connect the source array and the new array are the physical paths to transfer user data and system information. Upon the completion of Array Migration, you can access to the new array in the same way as you did to the other array.

See the Auto Migration help page for detailed instructions to complete the auto migration procedure.

Completing the Array Replacement Process   (back to top)

Completing the auto migration process includes two steps:

These steps are explained below.

Setting the Target Array to Normal Operation   (back to top)

To set the target array to normal operation:

  1. Turn off the power to both the source and target arrays.

  2. Disconnect the migration cables from both arrays.

  3. Change the setting of the migration switch on the target array to N.(normal operating mode). See the illustration in Setting up for Migration above.

  4. Turn the power on in the target array. Wait for the array to finish booting and the ready light to illuminate.

  5. In the Array List window, verify that the target array is running normally and that the IP address assigned to it is the same as he source array had before the auto migration process.

  6. Start I/O operations from the host to the target array.

Data Shredding   (back to top)

The Data Shredding function is a one step operation that deletes all the data and system information from a failed array. This process does more than just delete the data.  It destroys it so that it cannot be read or recovered by any means. This protects your data from being read by anyone when you send the array back to the factory to be repaired. Note that this process can take anywhere from minutes to hours to run, depending on the amount of data stored on the array.

See the Data Shredding help page for more information on data shredding, including detailed instructions to complete the procedure.

Resetting (releasing) the Migration Status   (back to top)

Reset Migration Status is a function that resets the migration status of a source array. If an auto-migration process failed to complete, you must reset the status on the source array before you can re-execute the process. See Resetting Array Migration Status help page for more information on this function.

 

See Also   (back to top)

The following topics within this help system provide information that may be helpful in understanding the information on this page, and/or may provide additional information that is related, but not required to understand this topic.

System Maintenance

Resetting Array Migration Status

Managing Storage