Imagine rebuilding an Vmware Esxi host from scratch after a crash—manually reconfiguring network settings, virtual switches, storage mappings, firewall rules, Vmware Esxi and services. It’s a painstaking task that’s not only time-consuming but highly prone to human error.
That’s where configuration backups come in. Backing up your ESXi host configuration ensures you can restore everything quickly and consistently in the event of a system failure, hardware replacement, or even when applying risky updates.
This guide walks you through how to back up and restore your ESXi host configuration using VMware’s native tools like ESXCLI, PowerCLI, and vCenter features. It also includes best practices, common pitfalls, and automation tips to help streamline the process.
What Is ESXi Host Configuration?
The ESXi host configuration refers to the settings and parameters that define how your ESXi host operates. This includes:
- Network settings (IP addresses, DNS, NIC teaming).
- Virtual switches and port groups.
- Storage configurations (datastores, mount points).
- Firewall and security settings.
- NTP and syslog settings.
- Licensing information.
- Enabled/disabled services.
Scope of Backup
It’s important to understand that esxi configuration backup do NOT include:
- Virtual machines (VMs) or their data.
- Datastore contents.
- Performance logs.
- Host logs or historical monitoring data.
Configuration backups are purely for restoring the host’s operating environment—not for full system recovery or VM-level backups.
Why Backup ESXi Host Configuration?
1. Disaster Recovery
If your ESXi host fails due to hardware issues, configuration corruption, or disk loss, having a backup means you don’t need to manually reconstruct settings from memory or documentation.
2. Hardware Migration
When moving configurations to a new server (e.g., hardware refresh), backups allow you to quickly replicate settings to the new hardware without reconfiguring everything manually.
3. Upgrades and Patching
Before applying updates or patches, backing up your configuration provides a restore point in case something goes wrong during the upgrade.
Methods to Backup ESXi Host Configuration
Using ESXCLI (Manual CLI Method)
Step-by-Step Guide:
Enable SSH on your ESXi host via the web UI or DCUI.
Connect via SSH (using PuTTY or any SSH client).
Run the following command:
vim-cmd hostsvc/firmware/backup_config
This generates a .tgz file, usually stored in:
/var/tmp/
Use SCP or the datastore browser to download the .tags file to your local machine for safekeeping.
Note: This method is best for occasional backups or single hosts.
Using PowerCLI (for Automation)
PowerCLI enables automated backup across multiple hosts, ideal for large environments.
Example PowerCLI Script:
Get-VMHost | ForEach-Object {
Get-VMHostFirmware -VMHost $_ -BackupConfiguration -DestinationPath “C:\ESXiBackups”}
This script retrieves the firmware configuration of each host and saves it to a local path. You can schedule it via Task Scheduler for routine backups.
Using vSphere Lifecycle Manager (vLCM) or Host Profiles
For environments managed by vCenter Server, Host Profiles and vSphere Lifecycle Manager can serve as backup tools.
- Host Profiles capture the desired state of a host’s configuration.
- vLCM can apply those profiles across clusters.
Pros: Centralized management, scalable.
Cons: Requires vCenter licensing; less granular than file-based backups.
How to Restore ESXi Host Configuration
Prerequisites
- The target ESXi version must match the one used during the backup.
- Basic networking must be manually configured first to allow SSH or SCP access.
- Host should be in maintenance mode or freshly installed.
Restore Using ESXCLI
- Boot into maintenance mode or perform a fresh ESXi install.
- Enable SSH and connect to the host.
- Upload your .tgz backup file to /tmp/ or /var/tmp/.
Run the command:
vim-cmd hostsvc/firmware/restore_config /tmp/configBundle.tgz
- The host will reboot automatically once the restore completes.
Restore Using PowerCLI
If you have PowerCLI connected to vCenter:
Set-VMHostFirmware -VMHost <hostname> -Restore -SourcePath “C:\ESXiBackups\configBundle.tgz” -Force
Tip: Ensure the host is in maintenance mode and matches the original configuration settings to avoid conflicts.
Best Practices for ESXi Configuration Backups
- Automate backups using scripts or scheduled tasks.
- Backup regularly (weekly or before any major update).
- Store off-host in remote, secure locations (e.g., S3 bucket, remote NAS).
- Keep multiple versions to roll back if needed.
- Test restore process in a sandbox environment to ensure reliability.
Limitations and What’s Not Included in the Backup
A configuration backup is not a full system backup. It excludes:
- VM data.
- VMX or VMDK files.
- Host logs or history.
- Any non-default installed VIBs (3rd-party drivers/plugins).
For complete protection, pair config backups with full VM backup solutions.
Tools That Simplify ESXi Backup & Restore
While VMware provides native tools, 3rd-party solutions can offer better automation and VM-level protection:
- Veeam Backup & Replication – Industry standard for VM and config backups.
- Trilead VM Explorer – Lightweight VM backup with host-level options.
- Altaro VM Backup – Offers granular backup, replication, and off-site storage.
- Custom PowerCLI Scripts – Tailor backups to your infrastructure and automate them easily.
Common Issues and Troubleshooting
- Version Mismatch: Backup and restore must be performed on the same ESXi version.
- Permission Errors: Ensure SSH, SCP, and shell access are enabled and not blocked by firewall rules.
- Corrupted tgz Files: Always verify file integrity after downloading.
- Incomplete Restore: Some settings may not apply correctly if the host’s hardware layout has changed significantly.
Conclusion
Backing up your VMware ESXi host configuration is a simple but crucial step in maintaining a stable and resilient virtual infrastructure. Whether you’re protecting against disasters, planning for hardware migrations, or preparing for updates, automated configuration backups give you peace of mind.
Start backing up today—it only takes a few minutes, and it can save hours or even days of rework in the future.
