Effect of Battery State on Cache Policy: 


               Secondary HSV    Secondary HSV   Secondary HSV 
               Battery Bad      Battery Low     Battery Good 


Primary HSV    no disk         All disks        All disks 
Battery bad    presentation    writethru        writeback 
               except SACD     on secondary     secondary 
                               HSV              HSV 


Primary HSV   all disks       all disks         all disks 
battery low   writethru on    writethru on      writeback 
              primary HSV     primary and       on secondary  
                              secondary HSV     HSV 


Primary HSV   all disks       all disks         all disks 
battery good  writeback on    writeback         writeback on 
              primary HSV     on primary HSV    primary and 
                                                secondary HSV 



The Storage Array Controller Device (SACD), located at LUN0 , is a special type of LUN defined by the SCSI-3 specification that serves as a portal to the controller, similar in function to the old Command Console LUN (CCL).

This information can be found in the EVA service manual.


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