NEC Storage Software PathManager, User Manual

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Chapter 3 Functions of NEC Storage PathManager
C:\>spscmd -getlun
*** LogicalUnit #0 ***
> 0: Priority=2, PathNumber=4:0:0:0
1: Priority=1, PathNumber=5:0:1:0
*** LogicalUnit #1 ***
X 0: Priority=1, PathNumber=4:0:0:1
> 1: Priority=2, PathNumber=5:0:1:1
+++ LogicalUnit #2 +++ [round robin]
> 0: Priority=2, PathNumber=5:0:1:2
@ 1: Priority=1, PathNumber=4:0:0:2
C:\>
/1/
/2/
/3/
/4/
A list of recognized paths is displayed for each logical unit. The image above shows that there are three
logical units and two paths are recognized for each of the logical units.
/1/ Logical unit number
This shows logical unit numbers and the state of load balancing. The logical unit that is dynamically
distributing the loads is displayed with a "+++" symbol before and after the logical unit number as seen in
LogicalUnit #2 in the above image. After the "+++" symbol attached to the end of the logical unit name, the
type of dynamic load balancing is displayed (NEC Storage PathManager 2.0 only supports "round robin" as a
type of dynamic load balancing). Other logical unit numbers are surrounded by the "***" symbol.
/2/ Path state
This shows the state of each path.
- ">": In use. This is the path that is currently being used.
- "X": Failed. This path is not used due to failures.
- "@": Standby. This path is on standby.
- No symbol: Active. This path is active.
/3/ Priority
This shows priorities given to the paths. Priority is used to specify the order of paths to be used in each
logical unit. For example, priority assigns a path to be used next when loads are dynamically distributed (in
the round robin method). In other cases, priority determines which path is to be used as an alternative in
case of failures in the paths currently in use.
Priority must be an integer between 1 and 254, and is uniquely determined in each of the logical units.
Priority becomes higher as the number becomes larger.
/4/ Path number
III-4
Path number uniquely assigns a path and is displayed in four numbers with a colon (:) in between. These
four numbers respectively correspond to PortNumber, PathId, TargetId, and Lun that are displayed in the -v
option.