IBM Support

Why is the status of hosts shown as Degraded in the 'lshost' command output in storwize V7000 Storage Node for data nodes in PureData for Operational Analytics appliance?

Question & Answer


Question

Why is the status of hosts shown as Degraded in the 'lshost' command output in storwize V7000 Storage Node for data nodes in PureData for Operational Analytics appliance?

Cause

The status of the hosts in Storwize V7000 storage nodes 'lshost' output is Degraded because in each V7000 Storage node the host is zoned only on the 4 ports out of the 8 available Fibre Channel(FC) ports in 2 Host based Adaptors(HBA), causing 4 of the remaining to be shown as offline.

Answer

The storage nodes in V7000 can be accessed using following ways:

1. Through V7000 Graphical User Interface where the status of the data nodes can be seen as Degraded as shown.

2. When lshost command is run on the storage node or in snap output from V7000 Storage Node, the same status Degraded can seen for all the data nodes in the cluster.

First V7000
IBM_2076:v7000_4:superuser>lshost
id name     port_count iogrp_count status
toucan06 8          4           degraded
1  toucan05 8          4           degraded

IBM_2076:v7000_4:superuser>lshost 0
id 0
name toucan06
port_count 8
type generic
mask 0000000000000000000000000000000000000000000000000000000000001111
iogrp_count 4
status degraded

WWPN 21000024FF6D4CFD
node_logged_in_count 0

state offline

WWPN 21000024FF6D4CFE
node_logged_in_count 2

state active

WWPN 21000024FF6D4C97
node_logged_in_count 2

state active

WWPN 21000024FF6D4C94
node_logged_in_count 0

state offline

WWPN 21000024FF6D4CFF
node_logged_in_count 2

state active

WWPN 21000024FF6D4C96
node_logged_in_count 2

state active

WWPN 21000024FF6D4CFC
node_logged_in_count 0

state offline

WWPN 21000024FF6D4C95
node_logged_in_count 0

state offline


Second V7000

IBM_2076:v7000_8:superuser>lshost
id name     port_count iogrp_count status
toucan06 8          4           degraded
1  toucan05 8          4           degraded
IBM_2076:v7000_8:superuser>lshost 0
id 0
name toucan06
port_count 8
type generic
mask 0000000000000000000000000000000000000000000000000000000000001111
iogrp_count 4
status degraded

WWPN 21000024FF6D4CFD
node_logged_in_count 2

state active

WWPN 21000024FF6D4CFE
node_logged_in_count 0

state offline

WWPN 21000024FF6D4C97
node_logged_in_count 0

state offline

WWPN 21000024FF6D4C94
node_logged_in_count 2

state active

WWPN 21000024FF6D4CFF
node_logged_in_count 0

state offline

WWPN 21000024FF6D4C96
node_logged_in_count 0

state offline

WWPN 21000024FF6D4CFC
node_logged_in_count 2

state active

WWPN 21000024FF6D4C95
node_logged_in_count 2

state active
 

This is because of the design and how the V7000 Storage Nodes are connected to the data nodes using the San Switches. Each data node has 2 Quad Port HBA, so 8 World Wide Port Name(WWPN) ports in total.

Each data nodes must be connected to the two V7000 Storage nodes to reduce the number of paths per LUN to 8 for best practices

The V7000 Storage Node has 8 FC ports which are in defined state because to each port you can see one of the two host's WWPN connected but half of them are always off-line. This causes the status of the Node Status from the V7000 perspective as Degraded for the data nodes. This should not be considered as a functional problem as this is due to the zoning of each HBA to two V7000 storage nodes.

[{"Product":{"code":"SSH2TE","label":"PureData System for Operational Analytics"},"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Component":["Not Applicable","Not Applicable"],"Platform":[{"code":"PF002","label":"AIX"}],"Version":"1.0","Edition":"All Editions","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
17 October 2019

UID

swg21691600