Output of multipath -ll
 

# multipath -ll

DATA01 (SVIOLIN_SAN_ARRAY_5C359C41E54B785F) dm-15 VIOLIN,SAN ARRAY
size=64G features='0' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=1 status=active
|- 3:0:0:13 sdn 8:208 active ready running
|- 3:0:1:13 sdaj 66:48 active ready running
|- 4:0:0:13 sdbk 67:224 active ready running
`- 4:0:1:13 sdci 69:96 active ready running

Can any one make understand whare are following things about above output:
(a) dm-15:
(b) features='0':
(c) hwhandler='0':
(d) wp=rw:
(e) prio=1:
(f) 3:0:0:13 sdn 8:208 active ready running


Thank you in advance..

Much of this you can get from: man multipath.conf

a) /dev/dm-15 is the multipath device
b) features is specified in /etc/multipath.conf (0 means none)
c) also from multipath.conf. Some devices need a helper program to switch paths
d) write permission (if known), rw = read/write, ro=read-only
e) prio=1 means all paths have equal priority (const)
f) SCSI address is adapter:channel:id:lun so scsi_host adapter 3, chan 0, target id 0, lun 13 is block device /dev/sdn which is kernel device major=8, minor=208, status active and running

Thank you very much small pond. I also googled and help to better understand of above answer. My last question, multipath device dm-15,what is this 15 means??