Article number
Affected Versions
Source Hypervisor
Target Hypervisor

Setting boot device on VM’s when recovering into SCVMM

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Root Cause

In SCVMM environments, Zerto does not set the boot device order by default. If the VM's being replicated are Generation 2 VM's (or are using UEFI firmware rather than BIOS in VMWare), this can lead to the incorrect disk or device being selected for first boot.


When performing a recovery operation (FailOver Test/Live, Move) into an SCVMM/Hyper-V environment, virtual machines may not boot to the correct device.


To workaround this issue, Zerto has created a method by which the first boot device can be statically assigned when recovering to an SCVMM environment.
**The workaround is applicable only to environments running Zerto 5.0 and above and will not work with any version prior to 5.0 **

To implement this, perform the following actions:

  1. In the machine running the Zerto Virtual Manager on the SCVMM site, open the file located in "C:Program FilesZertoZerto Virtual Replicationtweaks.txt". (Note: If you installed Zerto in a different drive from "C:", please navigate to the appropriate disk drive/installation directory).
    • Note: if the machine has 'Admin Approval Mode' enabled, you may need to open Notepad or your text editor as an administrator to be able to save the file after making changes
  2. In the file, add a new line below any existing content, and add one or all of the following entries.  Tweaks including "Gen2" in the String are for Generation 2 VMs, while ones without are for Generation 1 VMs.  Windows and Non Windows Operating Systems have their own tweaks.
    • t_firstBootDeviceWindowsVMs = "SCSI,0,0"
    • t_firstBootDeviceNonWindowsVMs = "SCSI,0,0"
    • t_firstBootDeviceGen2WindowsVMs = "SCSI,0,0"
    • t_firstBootDeviceGen2NonWindowsVMs = "SCSI,0,0"
  3. Save the file
  4. Perform the recovery operation

Note: You do not need to restart the Zerto Virtual Manager service for this change to take effect.

Additionally: the first boot device string can be changed, but the string should match one of the following formats: "SCSI,BusId(integer),LunId(integer)" or "NIC,SlotId(integer)" (e.g. "SCSI,0,0" or "NIC,0". Any changes made to this value will affect ALL VMs recovered to this environment which match the OS filter named in the tweak.