text: **7.1.7 Volume cache mode**
  
  Another adjustable volume parameter is its cache characteristics. Under normal conditions, a 
  volume’s read and write data is held in the cache of its preferred node, with a mirrored copy of 
  write data held in the partner node of the same I/O Group. However, it is possible to create a 
  volume with different cache characteristics, if this is required. 
  
  Cache setting of a volume can have the following values: 
  
  (cid:2)*readwrite*: All read and write I/O operations that are performed by the volume are stored in 
  cache. This is the default cache mode for all volumes. 
  
  (cid:2)*readonly*: Only read I/O operations that are performed on the volume are stored in cache. 
  
  (cid:2)*disabled*: No I/O operations on the volume are stored in cache. I/Os are passed directly to 
  the back-end storage controller rather than being held in the node’s cache. 
  
  Having cache-disabled volumes makes it possible to use the native copy services in the 
  underlying RAID array controller for MDisks (LUNs) that are used as IBM Spectrum Virtualize 
  image mode volumes. The use of IBM Spectrum Virtualize Copy Services rather than the 
  underlying disk controller copy services gives better results. 