Situatie
When performed by the Discovery Wizard or PowerShell cmdlets, the discovery of UNIX and Linux agents in Operations Manager typically involves three activities:
- Agent deployment
- Certificate signing
- Discovery of the agent
Agent deployment and certificate signing are performed using ssh, but these steps can also be performed finally. The final agent discovery is performed using a WS-Management query to the deployed agent. The discovery process may fail due to configuration issues, credential or privilege problems, or network and name resolution problems.
This document describes common errors that may be encountered during the discovery process, with potential causes and resolution steps.
Simptome
Certificate Errors/Certificate Signing Errors
Signed certificate verification operation was not successful
Error Description
Agent verification failed. Error detail: The server certificate on the destination computer (lx1.contoso.com:1270) has the following errors:
The SSL certificate could not be checked for revocation. The server used to check for revocation might be unreachable.
The SSL certificate contains a common name (CN) that does not match the hostname.
It is possible that:
- 1. The destination certificate is signed by another certificate authority not trusted by the management server.
- 2. The destination has an invalid certificate, e.g., its common name (CN) does not match the fully qualified domain name (FQDN) used for the connection. The FQDN used for the connection is: lx1.contoso.com.
- 3. The servers in the resource pool have not been configured to trust certificates signed by other servers in the pool.
Possible Causes
- The agent certificate’s CN value does not match the provided or resolved Fully-Qualified Domain name
Resolutions
- For certificate CN failures, confirm that that agent host’s hostname and domain name match the Fully-Qualified Domain Name resolved through DNS. More information can be found
Solutie
The SSL certificate could not be checked for revocation
Error Description
The server certificate on the destination computer (lx1.contoso.com:1270) has the following errors:
The SSL certificate could not be checked for revocation. The server used to check for revocation might be unreachable.
The SSL certificate contains a common name (CN) that does not match the hostname.
It is possible that:
1. The destination certificate is signed by another certificate authority not trusted by the management server.
- 2. The destination has an invalid certificate, e.g., its common name (CN) does not match the fully qualified domain name (FQDN) used for the connection. The FQDN used for the connection is: lx1.contoso.com.
- 3. The servers in the resource pool have not been configured to trust certificates signed by other servers in the pool.
Possible Causes
- The certificate has been signed by an untrusted authority, when multiple Management Servers are members of the Resource Pool used for discovery, but certificate trust has not been configured between the Management Servers.
Resolutions
- Confirm that all Management Servers in the Resource Pool used for Discovery trust each other server’s certificate. More information can be found .
Certificate signing operation was not successful
Possible Causes
- The user account specified for discovery has insufficient privileges to perform file operations involved in signing
- Sudo elevation privileges for the user account specified for discovery was not correctly configured
Resolutions
- Inspect the StdErr output in the error details to identify the cause of the failure
- Verify sudo privilege configuration for the account used for certificate signing
Network/Name Resolution Errors
The target address is not resolvable
Error Description
Failed to resolve IP address 192.168.25.25 to name
Possible Causes
- An IP Address for the host was entered for discovery, but is not resolvable to name in DNS (reverse lookup)
- Correct name resolution (DNS) configuration for reverse lookup
Failed to resolve name
Error Description
Failed to resolve name lxbad.test.com to IP address
Possible Causes
- An FQDN for the host was entered for discovery but is not resolvable to IP Address in DNS (forward lookup)
Resolution
- Correct name resolution (DNS) configuration for forward lookup
DNS configuration: forward DNS resolution does not match reverse DNS resolution
Error Description
The provided hostname host1 resolved to the IP address of 10.137.216.102. The hostname lx1.contoso.com returned by reverse lookup of the IP address 10.137.216.102 did not match the provided hostname. Verify the DNS configuration and try the request again.
Possible Causes
- Forward and reverse DNS lookups do not match
Resolutions
- Correct name resolution (DNS) configuration for forward and/or reverse lookup
The target address is unreachable
Error Description
The WinRM client cannot complete the operation within the time specified. Check if the machine name is valid and is reachable over the network and firewall exception for Windows Remote Management service is enabled.
Possible Causes
- The host is unreachable due to incorrect name resolution, network outage, or host outage
- A network or host-based firewall is blocking TCP port 1270 connectivity to the target host
Resolutions
- Verify that Management Server can ping the agent host by Fully-Qualified Domain Name
- Verify that no network firewalls or host firewall is blocking TCP port 1270
SSH Connectivity Errors
SSH connection error
Error Description
Failed during SSH discovery. Exit code: -1073479162
Standard Output:
Standard Error:
Exception Message:An exception (-1073479162) caused the SSH command to fail - No connection could be made because the target machine actively refused it.
Possible Causes
- The ssh daemon is not running on the target system
- A network or host-based firewall is preventing ssh connections on TCP port 22
- Verify that the ssh daemon is running
- Verity that no network firewalls or host firewall is blocking TCP port 22
Failed during SSH discovery (Exit code: -1073479118)
Error Description
Failed during SSH discovery. Exit code: -1073479118
Standard Output:
Standard Error:
Exception Message:An exception (-1073479118) caused the SSH command to fail - Server sent disconnect message: type 2 (protocol error : Too many authentication failures for root)
Possible Causes
- The user account specified for discovery is not permitted to login via ssh.
- The user account specified for discovery was input with an invalid username or password
- Verify that the user is permitted to login via ssh
- Verify the input credentials and that the user is defined on the target host
Failed during SSH discovery. Exit code: 1
Error Description
Failed during SSH discovery. Exit code: 1
Standard Output: Sudo path: /usr/bin/
Standard Error: sudo: sorry, you must have a tty to run sudo
Exception Message:
Possible Causes
- Sudo elevation was selected in the user credential input, but the requiretty option was not disabled for the user in sudoers.
Resolutions
- Edit the sudoers file on the target host (using the visudo command) and add the following line, replacing “” with the name of the user account specified for discovery:Defaults: !requiretty
Invalid SU password
Error Description
.[?1034hopsuser@lx1:~> su – root -c ‘sh /tmp/scx-opsuser/GetOSVersion.sh; EC=$?; rm -rf
/tmp/scx-opsuser; exit $EC’
Password:
exit
su: incorrect password
opsuser@lx1:~> exit
logout
Possible Causes
- Su elevation was selected in the user credential input, but an invalid root password was provided for su elevation
Resolutions
- Verify the password input for root in the Elevation configuration dialog
Failed during SSH discovery. Exit code: -2147221248
Error Description
Failed during SSH discovery. Exit code: -2147221248
Standard Output:
Standard Error: Could not chdir to home directory /home/username: No such file or directory
Possible Causes
- The user account specified for discovery does not have a home directory
Resolutions
- Verify that the user has a home directory at: /home/ and that the user is able to write to this directory
Failed during SSH discovery. Exit code: -2147221248
Error Description
Failed during SSH discovery. Exit code: -2147221248
Standard Output:
Standard Error: root’s password:
Exception Message:Operation timed out
Possible Causes
- Sudo elevation was selected in the user credential input, but the user account specified for discovery is not correctly configured to use passwordless sudo elevation or the required sudo elevation privileges were not granted for the user account used in discovery.
Resolutions
- Review sudo elevation configuration documentation and verify user configuration for sudo. Note that passwordless sudo must be configured.
WSMan Connectivity Errors
Invalid credentials
Error Description
The agent responded to the request but the WSMan connection failed due to : Access is Denied.
Possible Causes
- The agent is installed, and the agent certificate has been signed, but the user credential provided for agent verification is invalid.
- The user account specified for discovery was configured to authenticate with an ssh key, but the user credential provided for agent verification is invalid.
Resolutions
- Verify that the username and password for agent verification were input correctly and that the user is a valid user on the target host.
The target address is unreachable
Error Description
WSMan Only Discovery failed for 192.168.1.30
Possible Causes
- The Discovery Type option was set to “Only computers with an installed agent and signed certificate,” the target host has the agent installed, but the target host certificate has not been signed. In order to use the WSMan-only “Only computers with an installed agent and signed certificate” option, the agent must be installed and the certificate manually signed.
- The Discovery Type option was set to “Only computers with an installed agent and signed certificate,” but the target host does not have the UNIX/Linux agent currently installed.
- The Discovery Type option was set to “Only computers with an installed agent and signed certificate,” but the UNIX/Linux agent is not currently running.
- The Discovery Type option was set to “Only computers with an installed agent and signed certificate,” but the target host is unreachable, a network or host-based firewall is preventing connectivity, or the UNIX/Linux agent is currently down.
Resolutions
- Manually sign the certificate
- Verify that the UNIX/Linux agent has been installed
- Change the option to “Discover all computers” to allow the Discovery Wizard to perform the certificate signing
- Verify that the UNIX/Linux agent is running and that the target host is reachable
- Verify that no network firewalls or host firewall are preventing access on TCP port 127.
Other Errors
Agent deployment operation was not successful
Error Description
The task cannot be executed against the object(s) because the target of the task does not match any of the classes of the object.
Possible Causes
- In a System Center 2012 – Operations Manager management group, the UNIX/Linux management packs imported are Operations Manager 2007 R2 versions.
- Import the System Center 2012 versions of the UNIX/Linux operating system management packs.
No actions are available
Error Description
The agent is installed and the computer is already being monitored by Operations Manager.
Possible Causes
- The target host has already been discovered in this Management Group
Resolution
- No action is required. Agent upgrade or migration to an alternate resource pool can be performed from the UNIX/Linux Servers view in the Administration pane of the Operations Console
Platform not supported
Error Description
Failed to find a matching supported agent instance in the imported management packs.
Import the Management Pack(s) for this platform in order to discover this computer.
Possible Causes
- The target host is running an unsupported operating system.
- The correct management pack for the target host’s operating system has not been imported.
- The correct management pack for the operating system has recently been imported, and has not yet fully loaded.
Resolutions
- Confirm that the target host is running a supported operating system.
- Import the management pack for the target host’s operating system and version
- If the management pack was just imported, it may still be loading. Wait a few minutes and rerun discovery.
Pool Not Initialized
Error Description
Unable to enumerate Installable agent types. The associated resource pool may still be initializing. If you had selected a newly created resource pool, please wait a few minutes before using it.
Possible Causes
- The Resource Pool used in discovery is not healthy (a majority of member servers are offline).
- The Resource Pool used in discovery was recently created but has not fully initialized.
- If the Resource Pool used in discovery was recently created, retry the discovery after several minutes to allow the pool to initialize.
- Otherwise, check the Operations Manager Event Log on the servers that are members of the Resource Pool used for discovery for indications of problems.
< en-US, Linux, Operations Manager 2012, System Center 2012, Unix, OpsMgr 2012, SCOM 2012 >
Unable to copy new agent to this computer
Error Description
Message: Unable to copy new agent to this computer
Details:
Failed to copy kit. Exit code: -1073479144
Standard Output:
Standard Error:
Exception Message: An exception (-1073479144) caused the SSH command to fail
Possible Causes
- Latest verified occurrence: 7.5.1038.0
- File agent version mismatch between database and agent repository
Resolutions
- Try to update the failed agents again. Usually, the list of failed will get shorter and shorter during every update iteration
- Verify that the failed ones are all failing because of this issue. Otherwise, you’ve to apply other troubleshooting steps.
- Restart the Health Service on all members of your Linux Resource Pool or other Pool for managing UnixLinux machines. Check %ProgramFiles%Microsoft System Center 2012 R2Operations ManagerServerAgentManagementUnixAgentsDownloadedKits folder if file names are correct. Remember to close and re-open Discovery Wizard.
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