Using “Export to image mode” allows you to migrate data by using the Copy Services  functions and then return control to the native array, while maintaining access to the hosts. This option allows you to import an existing storage MDisk or logical unit number (LUN)  with its existing data from an external storage system, without putting metadata on it.  The existing data remains intact. After you import it, the volume mirroring function can be  used to migrate the storage to the other locations, while the data remains accessible to  your hosts.  This option allows any volume to be cloned without any interruption to the host access.  You have to create two mirrored copies of data and then break the mirroring with the split  option to make two independent copies of data. This option doesn’t apply to already  mirrored volumes. This option allows any volume to be moved between storage pools without any interruption  to the host access. You might use this option to move volumes as an alternative to the  Migrate to Another Pool function. Compared to the Migrate to Another Pool function,  volume mirroring provides more manageability because it can be suspended and resumed  anytime, and also it allows you to move volumes among pools with different extent sizes.  This option doesn’t apply to already mirrored volumes. Use Case:  Volume Mirroring can be used to migrate volumes from and to Data  Reduction Pools, which do not support extent based migrations. See 3.7.5, “Data  migration with DRP” on page 133. This option allows you to modify the capacity saving characteristics of any volume from  standard to thin provisioned or compressed and vice versa, without any interruption to  host access. This option works the same as the volume pool migration but specifying a  different capacity saving for the newly created copy. This option doesn’t apply to already  mirrored volumes. When you use Volume Mirroring, consider how quorum candidate disks are allocated. Volume  Mirroring maintains some state data on the quorum disks. If a quorum disk is not accessible  and Volume Mirroring is unable to update the state information, a mirrored volume might need  to be taken offline to maintain data integrity. To ensure the high availability of the system,  ensure that multiple quorum candidate disks, which are allocated on different storage  systems, are configured. Quorum disk consideration:  Mirrored volumes can be taken offline if there is no quorum  disk available. This behavior occurs because synchronization status for mirrored volumes  is recorded on the quorum disk. To protect against mirrored volumes being taken offline,  follow the guidelines for setting up quorum disks. The following are other Volume Mirroring usage cases and characteristics: GLYPH<SM590000> Import to Image mode GLYPH<SM590000> Volume cloning using Volume Mirroring and then using the Split into New Volume option GLYPH<SM590000> Volume pool migration using the volume mirroring option GLYPH<SM590000> Volume capacity saving change GLYPH<SM590000> Creating a mirrored volume: – The maximum number of copies is two. Chapter 5. Copy services  271