User guide

© DataDirect Networks 2011. Multipath (V1.8) User Guide | 18
# multipath -ll
mpath19 (360001ff0721160000000002688e10002) dm-2 DDN,S2A 6620
[size=21T][features=1 queue_if_no_path][hwhandler=0][rw]
\_ round-robin 0 [prio=50][active]
\_ 1:0:0:2 sdg 8:96 [active][ready]
\_ round-robin 0 [prio=10][enabled]
\_ 2:0:0:2 sdf 8:80 [active][ready]
Path Group 2
\_ round-robin 0 [prio=10][enabled]
\_ 2:0:0:2 sdf 8:80 [active][ready]
The example above shows a second path group to the same device (referenced in Path Group
1) within the Priority Group. This path group has a lower priority (prio=10) than path group 1
(prio=50). The path group state of this path group is enabled, meaning it is ready to service
IO, but is not the optimal path to send IO requests through. The physical path state is ready
to accept IO requests and the device mapper path state is active, which infers the path was
last tested successfully.
8. S2A 6620 EXAMPLE
The figure below identifies the relationships between linux SCSI devices, S2A 6620 virtual disks,
presentations, and dm-multipath devices.