VMware: A PowerCLI module to massively backup/restore ESXi hosts configurations

Flexibility is one of the greatest advantages of ESXi. Almost every aspect can be customized and tuned using both basic and advanced configurations in order to achieve a custom tailored system.

Configuring settings is a time consuming process, networking configurations for virtual standard switches, iSCSI vmkernel, port binding, NTP configuration, etc.

In case of host reinstall you can save precious time by using a great PowerCLI cmdlet: Get-VMHostFirmware.

This cmdlet creates a tar compressed archive containing all ESXi host's configurations. Conversely, to recover a backupped configuration, Set-VMHostFirmware cmdlet is used.

In this blog post I provide a PowerCLI module that will allow you to backup, and eventually restore, ESXi hosts configurations.

This module uses Get-VMHostFirmware and Set-VMHostFirmware cmdlets introducing the possibility to pass more than a single host as source for backup or target for restore and automatically enters/exits each host into/from maintenance mode before and after a backup restore occurs.

Let's start by briefly explaining how to use the module:

Typically the first step is to connect to a vCenter Server via PowerCLI in order to be able to perform backup or restores of one or more vCenter registered hosts. PowerCLI connection to a single ESXi host is also supported but for obvious reasons you can backup/restore only that specific host.

Once downloaded the script provided below you will have a .psm1 file, which is the common extension for PowerShell modules, that must be imported into PowerCLI in order to use it.

 Import-Module C:\Users\Paolo\WindowsPowerShell\Modules\BackupRestore  

Where C:\Users\Paolo\WindowsPowerShell\Modules\ is the path of BackupRestore.psm1 file on your PC.

BackupRestore module introduces into PowerCLI two new functions: Backup-VMHost and Restore-VMHost.

Backup-VMHost requires as mandatory parameters:

-VMHost: backup source. IP address or FQDN of one or more ESXi hosts you want to backup configurations from.
-FilePath: location where configuration bundles will be saved.

The following example backups the configuration of host 192.168.243.143 and 192.168.243.144 then save their configurations into C:\Users\Paolo\Desktop.

 Backup-VMHost -VMHost 192.168.243.143,192.168.243.144 -FilePath C:\Users\Paolo\Desktop  

Restore-VMHost requires:

-VMHost: Restore destination. IP address or FQDN of one or more ESXi hosts you want to recover configurations to.

-FilePath: location where configuration bundles can be fetched in order to be restored on host(s)

-HostUsername: ESXi host username

-HostPassword: ESXi host password

The following command will first place each host into maintenance mode then restore configuration bundle on ESXi host 192.168.243.143 and 192.168.243.144 taking it from C:\Users\Paolo\Desktop folder.

By default configuration bundles are saved as configBundle-<ESXi_host_IP_address>.tar (for example: configBundle-192.168.243.143.tar) so Restore-VMHost function expects such named files to be present in source folder.
Finally it will wait a few minutes (3 by default), giving to each host time to perform a reboot, then removes host from maintenance mode.

 Restore-VMHost -VMHost 192.168.243.143,192.168.243.144 -FilePath C:\Users\Paolo\Desktop -HostUsername root -HostPassword vmware  

As usual this code is also available on my GitHub repository: BackupRestore.psm1



That's all!!