Article number
Affected Versions
Source Hypervisor
Target Hypervisor

Error: “A Specified Parameter was not Correct: spec.memoryAllocation.reservation” when Performing a Failover Test/Failover/Move

Viewed 1956 times


An administrator may encounter a Failover/Move failing altogether or issues with NICs on a Recovery VM when there are required resource reservations configured on the Protected VM.

Root Cause

Zerto at this time does not support memory reservation for recovered VMs. The error encountered prevents VMWare Tools from processing any further operations (such as Re-IP functionality).

This VMWare KB Article discusses this error in further detail.


The following error may be presented to the administrator when performing a DR operation such as a Failover Test:

failed to ExecuteVmToolsOperations from CreateRecoveryVMsAndViewRecoverBeforeCommit: task id: urn:vcloud:task:dcd0671e-27ce-4a64-8473-76e6833c8af0 with operation vappUpdateVm on <vApp_URL> is error , due to : [ 055f3ef9-cff1-4ee4-94ff-69fe10c6b861 ] The operation could not be performed because the argument is invalid. A specified parameter was not correct: spec.memoryAllocation.reservation.

The administrator may also experience NICs not being attached to VMs upon recovery as well as NICs not having the expected IP Addresses as configured in the VPG settings.


To workaround this issue to allow for proper recovery of VMs, kindly follow the below steps:

  1. Open the vSphere Web UI on the Protected Site.

  2. Right click on the VM and select "Edit Settings".

  3. Expand the CPU and Memory fields. This should show reservation configuration. See example screenshot below that shows a VM with no reservations at all.

  4. Uncheck the checkbox "Reserve all guest memory".

  5. Retry the operation.

Memory Reservations