Dynamic volume migration 124  IBM DS8880 Architecture and Implementation More functions are associated with volume migration that allow the user to pause, resume, or  cancel a volume migration. Any or all logical volumes can be requested to be migrated at any  time if available capacity is sufficient to support the reallocation of the migrating logical  volumes in their specified target extent pool. For more information, see  IBM DS8000 Easy  Tier (for DS8880 R8.5 or later) , REDP-4667. Each logical volume has a configuration state. To begin a volume migration, the logical  volume initially must be in the normal configuration state.  Dynamic volume migration provides the following capabilities: Important:  DVR in the same extent pool is not allowed in the case of a managed pool. In  managed extent pools, Easy Tier automatic mode automatically relocates extents within  the ranks to allow performance rebalancing. The Easy Tier application can also be used to  manually place volumes in designated tiers within a managed pool. For more information,  see  DS8870 Easy Tier Application , REDP-5014. In the current implementation, you can only move volumes between pools of the  same  extent size . The user can request DVR by using the Migrate Volume function that is available through the  DS Storage Manager GUI (DS GUI) or DS CLI. DVR allows the user to specify a target extent  pool and an EAM. The target extent pool can be a separate extent pool than the extent pool  where the volume is located. It can also be the same extent pool, but only if it is a non-hybrid  or single-tier pool. However, the target extent pool must be managed by the same DS8880  internal server. DVR allows data that is stored on a logical volume to be migrated from its currently allocated  storage to newly allocated storage while the logical volume remains accessible to attached  hosts.  Dynamic volume migration or dynamic volume relocation (DVR) is a capability that is provided  as part of the Easy Tier manual mode facility. GLYPH<SM590000> The ability to change the extent pool in which a logical volume is provisioned. This ability  provides a mechanism to change the underlying storage characteristics of the logical  volume to include the drive class (Flash, Enterprise, or Nearline), drive RPM, and RAID  array type. Volume migration can also be used to migrate a logical volume into or out of an  extent pool. GLYPH<SM590000> The ability to specify the extent allocation method for a volume migration that allows the  extent allocation method to be changed between the available extent allocation methods  any time after volume creation. Volume migration that specifies the rotate extents EAM  can also be used (in non-hybrid extent pools) to redistribute a logical volume’s extent  allocations across the existing ranks in the extent pool if more ranks are added to an  extent pool.