Managing an emulated filer
What an emulated filer is
An emulated filer is a software copy of the failed filer that is hosted by the takeover filer. You access the emulated filer in partner mode by using the partner command, as described in the following sections.
Management exceptions for emulated filers
You manage an emulated filer as you do any other filer, including managing disks, with the following exceptions, which are described in greater detail later in this section:
- An emulated filer can access only failed filer disks.
- Some commands are unavailable.
- Some displays differ from normal displays.
Accessing the emulated filer from the takeover filer
You access the emulated filer from the takeover filer 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 filer, and takeover mode, in which you manage the takeover filer.
- The partner command with a filer command as an argument executes the filer command on the emulated filer 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
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Action
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|---|
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1 |
From the partner prompt, enter the following command:
partner
Results:
The prompt changes to the partner mode prompt, which has the following form:
emulated_filer/takeover_filer>
Example
The following example shows the change from takeover mode to partner mode and back:
filer1(takeover)> partner
Login from console: filer2
filer2/filer1> Thu Aug 20 16:44:39 GMT [filer1: rc]:
Login from console: filer2
partner
Logoff from console: filer2
filer1(takeover)> Thu Aug 20 16:44:54 GMT [filer1: rc]:
Logoff from console: filer2
filer1(takeover)>
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Using the partner command with arguments
To use the partner command with a filer command as an argument, complete the following step.
Step
|
Action
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|---|
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1 |
From the partner prompt, enter the following command:
partner command
command is the filer command you want to initiate on the emulated filer.
Example
filer1(takeover)> partner cf status
filer2 has been taken over by filer1.
filer1(takeover)>
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Accessing the emulated filer remotely
You can also access the emulated filer remotely without using the partner command.
Using Telnet
With Telnet, you can directly access only the takeover filer.
To access the emulated filer by using a Telnet session, complete the following steps.
Step
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Action
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|---|
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1 |
Log in to the takeover filer.
|
|
2 |
Enter the following command:
partner
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Using a Remote Shell connection
To execute a command on the emulated filer using rsh, complete the following step.
Step
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Action
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|---|
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1 |
Enter the following command:
rsh failed_filer command
failed_filer is the name of the failed filer.
command is the filer command you want to run.
Example
In the following example, filer2 is the failed filer.
rsh filer2 df
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Emulated filer command exceptions
Almost all the commands that are available to a normal filer are available on the emulated filer. Some commands, however, are either unavailable or behave differently in emulated filer mode. The commands in the following subsections are the exceptions.
Unavailable commands
The following commands are not available on an emulated filer:
cf disable
cf enable
cf forcegiveback
cf forcetakeover
cf giveback
cf takeover
date date
halt
ifconfig partner
ifconfig -partner
ifconfig mtusize
license cluster
rdate
reboot
timezone name
Commands with different behaviors
The following table lists the commands that behave differently on an emulated filer than they do on a takeover filer and describes the behavior.
Command
|
Difference
|
|---|
ifconfig
[interface]
|
Displays the following:
- Emulated filer interface mappings based on the failed filer's /etc/rc file rather than the takeover filer interface mappings
- Emulated filer interface names rather than the interface names of the takeover filer that has performed the takeover
- Only interfaces that have been configured, rather than all interfaces, configured or not, as displayed on the takeover filer
|
mt
|
Uses the tape devices on the takeover filer because the failed filer has no access to its tape devices.
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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 filer in which it physically resides and an IP address for its partner filer in the cluster.
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sysconfig
|
When it displays hardware information, the sysconfig command displays information only about the hardware that is attached to the takeover filer. It does not display information about the hardware that is attached only to the failed filer. For example, the disk adapter information that the partner sysconfig -r command displays is about the disk adapters on the takeover filer.
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uptime
|
Displays how long the failed filer has been down and the host name of the takeover filer.
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vol status
|
When it displays hardware information, the vol status command displays information only about the hardware that is attached to the takeover filer. It does not display information about the hardware that is attached only to the failed filer. For example, the disk adapter information that the partner vol status -r command displays is about the disk adapters on the takeover filer.
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Copyright © 1994-2003, Network Appliance, Inc. All rights
reserved.
Part No. 210-00472
File: clust18.htm
Last updated: 11/17/03 16:57:48