Specifications

VMware, Inc. 187
Chapter 13 Troubleshooting
Symptom
The message java.io.IOException: An existing connection was forcibly closed by the remote
host appears in the active server's NFLog.txt file, and the VMware Channel connection between the servers
is lost.
Causes
This unusual condition points to an application or Windows experiencing a fault on the passive server. A
sudden restart of the passive server can occur due to the following causes:
 The server is configured for automatic software update management and some updates force the server
to restart
 A software or Operating System issue that occasionally fails and requires a system restart
 The Neverfail Server R2 service experiences problems, does not respond, or terminates unexpectedly
Resolution
To resolve the issue, make the following checks.
 Determine the likely source by examining the Windows event logs.
 If the server does not display evidence of a system restart or unresponsive application, one or both of the
VMware Channel NICs could be forcing a channel disconnection. See “Hardware or Driver Issues on
VMware Channel NICs” on page 187 for more information on this topic.
Passive Server Does Not Meet Minimum Hardware Requirements
Inadequate hardware can cause channel drops and result in poor performance.
Symptom
The data rate between the servers is very fast during a Full System Check and the VMware Channel drops.
Cause
The passive server does not meet the recommended hardware requirements for vCenter Server Heartbeat or
it meets the requirements, but is much less powerful than the active server. The underpowered server cannot
apply the received replication data from the active server at the rate that the data is sent to the passive server.
Resolution
To avoid reinstalling vCenter Server Heartbeat, upgrade the hardware, such as memory or CPU, on the passive
server. Establish the identity (Primary or Secondary) of the affected server before you perform the upgrade.
Hardware or Driver Issues on VMware Channel NICs
NIC malfunctions and old or incorrect drivers can cause channel drops resulting in poor performance.
Symptom
The VMware Channel intermittently drops or disconnects and reconnects.
Causes
The following are common causes of NIC problems.
 Old or incorrect VMware Channel NIC drivers
 Hardware failure of the hub or Ethernet switch used for the VMware Channel connection
 Defective Ethernet patch or crossover cables