Diagnosing problems with adding a member to a CacheGroup (Cacheflow appliance)

Products

• CacheFlow Appliance Software

Issue/Introduction

An attempt to have a CacheFlow appliance join an existing cache group as a member fails. Depending on the circumstances, the symptom may be an error message appearing or the appliance rebooting into initial configuration mode, requiring serial console or front panel access.

In general, a failure to join may be caused by three classes of problems:
• the manager rejecting the appliance,
• a problem downloading or applying a software update,
• or a failure to apply the manager’s configuration on the appliance.
The cause of the problem can be identified by the error message displayed.
 

Resolution

Appliance Rejected by Manager

The following error messages may appear in the event that the manager appliance does not allow the member to join:

1. % The peer is not a manager of this cache group

The manager IP address specified belongs to a CacheGroup member rather than to a manager.

Verify that the manager appliance IP address entered is correct. If the IP address definitely belongs to a CacheGroup Manager, contact Technical Support for further assistance.

2. % A duplicate IP address has been supplied for a network interface

An IP address configured on the appliance for one of the network interfaces is used by another cache group member.

There are two ways to resolve the problem:

a. Change the conflicting IP address on the member appliance prior to joining the group.
b. Override the IP settings for this member from the Manager. To do this, the member must be pre-added, for example:

#(config)cache-group manager
#(config cache-group)add member <serial number>
#(config cache-group)edit member <serial number>
#(config cache-group <serial number>)interface <adapter id>:<interface id> <IP address>

3. % An interface that is disabled on the manager cannot be enabled on a member

An interface has an IP address assigned on the appliance, but the same interface does not have an IP address assigned on the manager.

For example, this would happen if the appliance attempting to join the cache group has an IP address assigned for interface 0:2, while the manager appliance does not.

On the member appliance, remove IP addresses from all interfaces that do not have IP addresses on the manager.
 

4. % The IP is not on the same subnet as the manager

An interface has an IP address assigned on the appliance, and the IP address is not on the same subnet as the IP address assigned to the same interface on the manager.

For example, this would happen if on the manager interface 0:2 has IP address 10.0.0.2 with netmask 255.255.255.0, while interface 0:2 on the appliance joining the group has IP 10.0.1.2.

Replace the offending IP address with one that is on the same subnet as the IP address for that interface on the manager. This can either be done directly on the member, or this can be done from the manager (see 2b above).
 

5. % Member IP addresses for one or more interfaces enabled on the manager are missing

There is no IP address assigned for a certain interface on the member appliance, and an IP address for that interface for the appliance has not been pre-set on the Manager. However, the manager itself has an IP address configured on that interface.

For example, this would happen if interface 0:1 on the manager has an IP address assigned, but interface 0:1 on the appliance joining the group has no IP assigned and an IP for interface 0:1 for the joining appliance has not been pre-set on the manager using the 'interface' gesture in 'edit member' mode.

Ensure that for every interface that has an IP address assigned on the manager, an IP address is also assigned for the member. This can either be done directly on the member, or this can be done from the manager (see 2b above).
 

6. % This appliance is not recognized by the peer

The manager is running in strict authorization mode, and the serial number of the joining appliance has not been pre-added to the member list.

This problem can be solved be pre-adding the serial number of the member on the manager, as follows:
 

#(config)cache-group manager
#(config cache-group)add member <serial number>

Alternatively, the manager can be switched to open authorization mode. If the manager is running in open authorization mode, any CacheFlow appliance will be allowed to join the group. This can be accomplished as follows:

#(config)cache-group manager
#(config cache-group)authorization-mode open
 

7. % Cannot add more than 150 members to the cache group

The cache group already has more than 150 members.

No more than 150 appliances can belong to a cache group at any given time. The restriction cannot be circumvented. To add a new member, an existing one must first be removed.
 

Problems Applying Software Update

If the manager appliance and the appliance attempting to join are not running the same version of the CacheFlow software, the appliance cannot join unless the software is updated to match that of the manager. A prompt requesting permission to update the software would be presented in this case. Saying 'no' at the prompt will cause the join operation to fail.

Additionally, the following error messages may be displayed in the event of problems downloading or installing the CacheFlow software:

 

1. % No network path to system software specified on the manager

The member appliance will download the software from the URL specified in the upgrade-path on the manager. This error message indicates that no upgrade-path value is present on the manager.

Ensure that the upgrade-path value on the manager points to the same software image as the one currently running on the manager appliance, e.g.,

#(config)upgrade-path http://10.0.0.1/cf5000.chk.bcsi

 

2. % An error has occurred applying the update

The member appliance fails to load the specified software for whatever reason/

This will be followed with a more detailed error message elaborating on the nature of the problem, for example:

>  Downloading from "http://10.0.0.1/cf5000.chk.bcsi"
>  Connecting to download site
> % Unable to contact server specified in URL

Resolve any connectivity problems on the member appliance preventing the software download from completing successfully.
 

Problems Applying Configuration

If an error occurs replicating the manager's configuration on the newly-joined member appliance, the member's configuration will be reset and the appliance will be rebooted. This indicates a bug in the CacheFlow software, and Blue Coat Technical Support should be contacted and notified of the problem.

The syslog of an appliance that has experienced this problem will contain the following message:

'Error applying initial configuration. The appliance configuration is being reset.'

The appliance will need to be re-configured from the serial console or the front panel.

In the event of such an error, a log with the configuration commands that were applied to the member will be stored on the manager appliance. A list of all such logs can be obtained using the command ‘show cache-group member error-log list’. The list is in reverse chronological order. A log can be viewed using the command ‘show cache-group member error-log <id>’, where <id> is the number of the log in the list.

Please manually initiate a diagnostic upload from the manager appliance with the command

 # send-diagnostic

and report the problem to Blue Coat Technical Support.