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Resource type definition

type MultiNICB (

    static int OfflineMonitorInterval = 60

    static int MonitorInterval = 10

    static str ArgList[] = { Device, NetworkHosts, Gateway,
    LinkTestRatio, NoBroadcast, NetworkTimeout,
    OnlineTestRepeatCount, OfflineTestRepeatCount }

    static str Operations = None

    str Device{}

    str NetworkHosts[] = { "0.0.0.0" }

    str Gateway

    int LinkTestRatio = 1

    int NoBroadcast

    int NetworkTimeout = 100

    int OnlineTestRepeatCount = 3

    int OfflineTestRepeatCount = 3

)

Trigger script

MultiNICB monitor agent function calls a VCS trigger in case of an interface going up or down. The agent passes the following arguments to the script:

• MultiNICB resource name
• The device whose status changed, for example:
  • AIX: en0
• The device's previous status (0 for down, 1 for up)
• The device's current status and monitor heartbeat

The agent also sends a notification (which may be received via SNMP or SMTP) to indicate that status of an interface changed. The notification is sent using "health of a cluster resource declined" and "health of a cluster resource improved" traps. These traps are mentioned in the VCS User's Guide. A sample mnicb_postchange trigger is provided with the agent. You can customize this sample script as needed or write one from scratch.

The sample script does the following:

• If interface changes status, it prints a message to the console, for example:

  MultiNICB agent Res. Name: Device en0 status changed from Down to Up.

Manually reattach the MultiNICB agent interfaces after
failover

In order to prevent AIX from attempting to send packets through a broken interface (cable unplugged), the MultiNICB agent detaches the interface when it detects that the interface is down. When the interface is brought up (cable plugged in), you need to re-attach the interface to enable the agent to monitor it.

To attach the interface, type:

    # chdev -l interface -a state='up'

For example, if the fixed interface is en4, enter:

    # chdev -l en4 -a state='up'

Standby interfaces are the ones where the virtual IP is not configured. If a standby interface fails, the current agent does not detach it. Hence, if there are two interfaces within the MultiNICB resource, this can result in a 50% packet loss when the virtual IP address is pinged from within the subnet. No packet loss occurs if the virtual IP address is pinged from outside the subnet.

A workaround for this issue is to manually detach the broken interface and re attach it again after it is fixed.

The command to detach an interface is:

    # chdev -l interface -a state='detach'