If you created a primary volume on a legacy storage system that cannot be managed by SANtricity System Manager, you can create the secondary volume on this array with SANtricity System Manager.

About this task

You can perform asynchronous mirroring between legacy arrays that use a different interface and newer arrays that can be managed by SANtricity System Manager.

If you are mirroring between two storage systems that use SANtricity System Manager, you can skip this task because you already completed the mirrored pair in the mirrored pair creation sequence.
Perform this task on the remote storage system.

Steps

Select Storage > Asynchronous Mirroring.
Select the Mirrored Pair tab.

The Mirrored Pairs table appears and displays all the mirrored pairs associated with the storage system.
Find the mirrored pair volume with a status of Incomplete, and then click the Complete mirrored pair link displayed in the mirrored pair column.
Choose whether you want to complete the mirrored pair creation sequence automatically or manually by selecting one of the following radio buttons:
- Automatic
  Create new secondary volume.
  
  Accept the default settings for the remote side of the mirrored pair by selecting an existing pool or volume group where you want to create the secondary volume. Use this recommended option to allocate the reserved capacity for the secondary volume with the default settings.
- Manual
  Select an existing volume.
  
  Define your own parameters for the secondary volume.
  1. Click Next to select the secondary volume.
  2. Select an existing volume that you want to use as the secondary volume and then click Next to allocate the reserved capacity.
  3. Allocate the reserved capacity. Do one of the following:
    
    Accept the default settings.
    
    The default setting for reserved capacity is 20% of the capacity of the base volume, and usually this capacity is sufficient.
    
    Allocate your own reserved capacity settings to meet your data storage needs related to asynchronous mirroring.
    
    The capacity needed varies, depending on the frequency and size of I/O writes to the primary volume and how long you need to keep the capacity. In general, choose a larger capacity for reserved capacity if one or both of these conditions exist:
    
    You intend to keep the mirrored pair for a long period of time.
    
    A large percentage of data blocks will change on the primary volume due to heavy I/O activity. Use historical performance data or other operating system utilities to help you determine typical I/O activity to the primary volume.
Select Complete.

Results

SANtricity System Manager performs the following actions:

Creates the secondary volume on the remote storage system and allocates reserved capacity for the remote side of the mirrored pair.
Begins initial synchronization between the local storage system and the remote storage system.
If the volume being mirrored is a thin volume, only the allocated blocks are transferred to the secondary volume during the initial synchronization. This transfer reduces the amount of data that must be transferred to complete the initial synchronization.
Creates the reserved capacity for the mirrored pair on the local storage system and on the remote storage system.