IBM Midrange System DS4000 Series User Manual

Chapter 7. Advanced maintenance, troubleshooting, and diagnostics 463
In Example 7-13, we see a bad condition example, where:
򐂰 Both paths to controller B failed.
򐂰 LUN0 is owned by controller A, which is in the Optimal state.
򐂰 LUN1 is owned by controller B, which is in the failed state. LUN1 has been taken over by
controller A.
To correct these path issues, set the paths to controller B.
To relate the devices detected by Linux to the logical drives configured and mapped to your
host in the DS5000, use the mppUtil utility. You can use the LUN number listed and the WWN
string to determine the corresponding logical drive in your DS5000.
Example 7-13 mppUtil -g1 - controller failover
[root@TC-2008 ~]# mppUtil -g0
Hostname = TC-2008
Domainname = (none)
Time = GMT 10/01/2009 19:27:28
MPP Information:
----------------
ModuleName: ITSO_5020 SingleController: N
VirtualTargetID: 0x000 ScanTriggered: N
ObjectCount: 0x000 AVTEnabled: Y
WWN: 60080e500017b5bc000000004a955e3b RestoreCfg: N
ModuleHandle: none Page2CSubPage: Y
FirmwareVersion: 7.60.13.xx
ScanTaskState: 0x00000000
LBPolicy: LeastQueueDepth
Controller 'A' Status:
-----------------------
ControllerHandle: none ControllerPresent: Y
UTMLunExists: N Failed: N
NumberOfPaths: 2 FailoverInProg: N
ServiceMode: N
Path #1
---------
DirectoryVertex: present Present: Y
PathState: OPTIMAL
PathId: 77020000 (hostId: 2, channelId: 0, targetId: 0)
Path #2
---------
DirectoryVertex: present Present: Y
PathState: OPTIMAL
PathId: 77030000 (hostId: 3, channelId: 0, targetId: 0)
Controller 'B' Status:
-----------------------
ControllerHandle: none ControllerPresent: Y
UTMLunExists: N Failed: Y<--indicates
HW problem
NumberOfPaths: 2 FailoverInProg: N
ServiceMode: N

IBM Midrange System DS4000 Series Specifications

General

Brand	IBM
Model	Midrange System DS4000 Series
Category	Storage
Language	English