Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Using this device-mapper switch target we can now build a two-layer
device hierarchy:
- Upper Tier – Determine which array member the I/O should be sent to.
- Lower Tier – Load balance amongst paths to a particular member.
+ Upper Tier - Determine which array member the I/O should be sent to.
+ Lower Tier - Load balance amongst paths to a particular member.
The lower tier consists of a single dm multipath device for each member.
Each of these multipath devices contains the set of paths directly to