Managing an emulated node

What an emulated node is

An emulated node is a software copy of the failed node that is hosted by the takeover node. You access the emulated node in partner mode by using the partner command, as described in the following sections.

Management exceptions for emulated nodes

You manage an emulated node as you do any other storage system, including managing disks, with the following exceptions, which are described in greater detail later in this section:

An emulated node can access only its own disks.
Some commands are unavailable.
Some displays differ from normal displays.

Accessing the emulated node from the takeover node

You access the emulated node from the takeover node in takeover mode with the partner command. You can issue the partner command in two forms:

The partner command without an argument toggles between partner mode, in which you manage the emulated node, and takeover mode, in which you manage the takeover node.
The partner command with a Data ONTAP command as an argument executes the command on the emulated node in partner mode and then returns to takeover mode.

Using the partner command without arguments

To toggle between partner mode and takeover mode, complete the following step.

Step	Action
1	From the takeover prompt, enter the following command: partner Results: The prompt changes to the partner mode prompt, which has the following form: emulated_node/takeover_node> Example The following example shows the change from takeover mode to partner mode and back: filer1(takeover)> partner Login from console: filer2 Thu Aug 20 16:44:39 GMT [filer1: rc]: Login from console: filer2 filer2/filer1> partner Logoff from console: filer2 filer1(takeover)> Thu Aug 20 16:44:54 GMT [filer1: rc]: Logoff from console: filer2 filer1(takeover)>

Step

Action

From the takeover prompt, enter the following command:

partner

Results:

The prompt changes to the partner mode prompt, which has the following form:

emulated_node/takeover_node>

Example

The following example shows the change from takeover mode to partner mode and back:

filer1(takeover)> partner

Login from console: filer2

Thu Aug 20 16:44:39 GMT [filer1: rc]: Login from console: 
filer2

filer2/filer1> partner

Logoff from console: filer2

filer1(takeover)> Thu Aug 20 16:44:54 GMT [filer1: rc]: 
Logoff from console: filer2

filer1(takeover)>

Using the partner command with arguments

To use the partner command with a Data ONTAP command as an argument, complete the following step.

Step	Action
1	From the takeover prompt, enter the following command: partner command command is the command you want to initiate on the emulated node. Example filer1(takeover)> partner cf status filer2 has been taken over by filer1. filer1(takeover)>

Accessing the emulated node remotely

You can also access the emulated node remotely.

Using Telnet

With Telnet, you can directly access only the takeover node.

To access the emulated node by using a Telnet session, complete the following steps.

Step	Action
1	Enter the following command: telnet takeover_node
2	Log in to the takeover node.
3	Enter the following command: partner

Step

Action

Enter the following command:

telnet takeover_node

Enter the following command:

partner

Using a Remote Shell connection

To execute a command on the emulated node using rsh, complete the following step.

Step	Action
1	Enter the following command: rsh failed_node command failed_node is the name of the failed node. command is the Data ONTAP command you want to run. Example In the following example, filer2 is the failed node. rsh filer2 df

Emulated node command exceptions

Almost all the commands that are available to a takeover node are available on the emulated node. Some commands, however, are either unavailable or behave differently in emulated mode. The commands in the following subsections are the exceptions.

Unavailable commands

The following commands are not available on an emulated node:

cf disable
cf enable
cf forcegiveback
cf forcetakeover
cf giveback
cf takeover
date
halt
ifconfig partner
ifconfig -partner
ifconfig mtusize
license cluster
rdate
reboot
timezone

Commands with different behaviors

The following table lists the commands that behave differently on an emulated node than they do on a takeover node, and describes the behavior.

Command	Difference
ifconfig [interface]	Displays the following: Emulated interface mappings based on the failed node /etc/rc file rather than the takeover node interface mappings Emulated interface names rather than the interface names of the takeover node Only interfaces that have been configured, rather than all interfaces, configured or not, as displayed on the takeover node
mt	Uses the tape devices on the takeover node because the failed node has no access to its tape devices.
netstat -i	Appends a plus sign (+) to shared interfaces. A shared interface is one that has two IP addresses assigned to it: an IP address for the node in which it physically resides and an IP address for its partner node in the cluster.
sysconfig	When it displays hardware information, the `sysconfig` command displays information only about the hardware that is attached to the takeover node. It does not display information about the hardware that is attached only to the failed node. For example, the disk adapter information that the `partner sysconfig -r` command displays is about the disk adapters on the takeover node.
uptime	Displays how long the failed node has been down and the host name of the takeover node.
aggr status	When it displays hardware information, the `aggr status` command displays information only about the hardware that is attached to the takeover node. It does not display information about the hardware that is attached only to the failed node. For example, the disk adapter information that the `partner aggr status -r` command displays is about the disk adapters on the takeover node.