text: **System-wide settings**
  There is a system-wide setting*Easy Tier acceleration*that is disabled by default. Turning it on 
  makes Easy Tier move extents up to four times faster than the default setting. In accelerate 
  mode, Easy Tier can move up to 48 GiB per 5 minutes, whereas in normal mode it moves up 
  to 12 GiB. The following use cases are the most probable use cases for acceleration: 
  
  (cid:2) When adding capacity to the pool, accelerating Easy Tier can quickly spread volumes onto 
  the new MDisks. 
  
  (cid:2) Migrating the volumes between the storage pools when the target storage pool has more 
  tiers than the source storage pool, so Easy Tier can quickly promote or demote extents in 
  the target pool. 
  
  **Note:**Enabling Easy Tier acceleration is advised only during periods of low system activity 
  only after migrations or storage reconfiguration occurred. It is recommended to keep Easy 
  Tier acceleration mode off during normal system operation. 
  
  This setting can be changed online, but only by using the CLI. To turn on or off Easy Tier 
  acceleration mode, use the**chsystem**command. Use the**lssystem**command to check its 
  current state, as shown in Example 10-5. 