How to create persistent cache
==============================

EnhanceIO caches are persistent by default. A udev rule file named
94-enhanceio-<cache_name>.rules is created, removed by create, delete
sub-commands in eio_cli.

Note
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1) Creating a writeback cache on root device is not supported. This is because
   the root device is mounted as read only prior to the processing of udev
   rules.
 
2) For certain devices such as loop device the udev rule file will not be
   generated
