Configuration Issue: No Coredump Target Set – Host Core Dumps Cannot Be Saved
Key Notes
- Core dump target configuration is crucial post-host updates.
- Creating empty dump files is the first step towards configuration.
- Enabling core dump on external storage requires specific configurations.
Troubleshooting Core Dump Configuration in VMWare After Host Update
VMWare users often face core dump configuration issues after upgrading their host systems. These problems can cause significant interruptions and debugging challenges. This guide provides actionable steps to resolve the “no coredump target” warning encountered during Esxcli operations.
Resolving Core Dump Configuration Issues
If you encounter the warning stating “The core dump target has not been configured, ” follow the steps below to address the situation effectively.
Step 1: Create Core Dump Files for Your ESXi Hosts
If your ESXi hosts utilize iSCSI storage, including SAN boot, you must establish dump files for them.
Initiate the process by making an empty dump file with the following command:
esxcli system coredump file add -d *your_datastore_name* -f *the_dumpfile_name(typically, using the ESXi hostname)*
Next, designate your newly created file as the active dump file:
esxcli system coredump file set -p /vmfs/volumes/*your_datastore_name*/vmkdump/*the_dumpfile_name*.dumpfile
To verify the creation of your dump file, execute:
esxcli system coredump file list
Pro Tip: Ensure that your ESXi host has sufficient storage to accommodate the dump files.
Step 2: Enable Core Dump on USB and Create a Partition
For users utilizing USB for core dump, it is necessary to enable and configure it. Follow these steps:
- Navigate to the warning, then go to Configure System > Advanced System Settings.
- Click on the Edit button, filter for VMkernel. Boot.allow and locate VMkernel. Boot.allowCoreDumpOnUsb.
- Set the value of VMkernel. Boot.allowCoreDumpOnUsb to true.
- After connecting to the host via SSH, run
esxcli storage filesystem listto view available local storage locations of type VMFS-L. - Execute
esxcli system coredump file add -d DATASTORE -f HostName -s 2000to create the core dump file. - Run
esxcli system coredump file listto confirm the core dump file’s creation. - If it shows False under Active, enable it by executing
esxcli system coredump file set -s -e=True.
Pro Tip: Regularly check the configurations to prevent future issues.
Step 3: Disable the Warning Message
If the warning message is bothersome and you wish to disable it, navigate to ESXi Host > Configuration > Advanced Settings, find UserVars. SuppressCoredumpWarning, and set its value to 1.
Pro Tip: Disabling warnings may prevent you from receiving critical notifications about core dump configurations.
Additional Tips for Effective Configuration
- Ensure that your backups are updated before changing core dump settings.
- Consult VMWare documentation for specific configurations based on your hardware setup.
- Monitor core dump activity regularly for optimal performance.
Summary
Proper core dump configuration is essential for troubleshooting core issues in VMWare environments. Following the outlined steps ensures that core dumps are correctly saved and accessible, thus facilitating easier analysis and problem resolution.
Conclusion
By effectively managing your core dump configurations post-update, you can prevent potential data loss and ensure your system’s reliability. Follow these guidelines closely and feel free to consult the community if challenges persist.
FAQ (Frequently Asked Questions)
How do I configure core dump on vCenter?
To set up core dumps on vCenter, navigate to Home > Administration > System Configuration > Services, select the ESXi Dump Collector service, and ensure it’s enabled via the Actions menu.
What is a core dump file in VMware?
Core dump files are crucial for debugging ESX host issues, specifically during kernel panic situations. Starting from VMWare ESX version 5.5, users can generate core dumps directly to a file, enhancing flexibility compared to traditional options.