QFARM Does Not List the Same Number of Servers as Qfarm/load

Description

Citrix Administrator runs the CLI commands QFARM and QFARM /LOAD in a two server farm, the command QFARM displays only one server but the command QFARM /LOAD displays the load of two servers.
Command Prompt

Troubleshooting Methodology

The CLI command dscheck /full servers lists the servers with no errors (the preceding commands failed to list the following servers):

Using Citrix Quick Launch utility, the ICA desktop of the absent server (in the QFARM list) started successfully. Through the port 2598 in telnet, the connection to the server is successful but not through the port 1494.
Note: The Cause-1 and Solution-1 are applicable for this scenario only.

Environment

Caution! Using Registry Editor incorrectly can cause serious problems that might require you to reinstall your operating system. Citrix cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. Be sure to back up the registry before you edit it.

Resolution

Solution-1

To resolve the issue, recreate the ICA listener on the server by exporting the ICA listener registry key from the second server and importing into the first one.

Caution! Refer to the Disclaimer at the end of this article before using Registry Editor.

The registry key for the ICA listener is located in path “HKEY_ LOCAL _ MACHINE\SYSTEM \Control Set\Control\Terminal Server\WinStations\ICA-tcp”.

Solution-2

Modify the magic number of the impacted server registry to match the magic number on data store.
OR
Import the registry key from another server of the farm. The magic number is described in the following registry key location: HKLM\SOFTWARE\Wow6432Node\Citrix\IMA\Data

Note: If the number is not visible, enable permission to view that registry key.

Problem Cause

Cause-1

The ICA listener does not list the server when issuing the QFARM command because of the following reasons:

QFARM uses Independent Management Architecture (IMA) to collect data from the data store using the port 1494 and the listener was partially corrupted.
The QFARM /LOAD (or any other switch) uses the Zone Data Collector (ZDC) to collect the load from all the servers.

Cause-2

In any large farm (more than one server), the mismatch in magic number between the missing server and the server listed in the farm causes the issue.
Notes:

The magic number or magic key is a unique 32 bit number assigned to a newly created farm to indicate that all servers are in the same farm.
The magic number must be same in all servers. Otherwise the command QFARM might not enumerate the server with the mismatching magic number.