Disaster Scenarios and Their Handling

 

 

Table 4-1

Disaster Scenarios and Their Handling (Continued)

 

 

 

 

Disaster Scenario

What Happens When

Recovery Process

This Disaster Occurs

 

 

 

 

 

 

A package (P1) is running on a

The package (P1) fails over

Complete the following procedure

node (Node 1). The package uses

to Node 2 and starts

to initiate a recovery:

a mirror (md0) that consists of

running with the mirror of

1. Restore data center 1, Node 1

two storage components - S1

md0 that consists of only

(local to Node 1 -

 

the storage local to node 2

and storage 1. Once Node 1 is

/dev/hpdev/mylink-sde) and

(S2).

restored, it rejoins the cluster.

S2 (local to Node 2)

 

 

Once S1 is restored, it

Data center 1 that consists of

 

becomes accessible from Node

 

2.

Node 1 and P1 experiences a

 

 

When the package failed over

failure.

 

 

NOTE: In this example, failures

 

and started on Node 2, S1 was

 

not a part of md0. As a result,

in a data center are

 

 

you need to add S1 into md0.

instantaneous. For example -

 

Run the following command to

power failure.

 

 

add S1 to md0:

 

 

 

# mdadm – -add /dev/md0

 

 

 

/dev/hpdev/mylink-sde

 

 

 

The re-mirroring process is

 

 

 

initiated. When it is complete,

 

 

 

the extended distance cluster

 

 

 

detects the added mirror half

 

 

 

and accepts S1 as part of md0.

 

 

 

2. Enable P1 to run on Node 1 by

 

 

 

running the following

 

 

 

command:

 

 

 

# cmmodpkg -e P1 -n N1

 

 

 

 

88

Chapter 4