Symptoms:

After the preseed disk was created and shipped to the recovery site, the size of the original disks was increased.

This article explains how to handle properly the cloned preseed volumes. 

Solution:

One possible solution is to use vmkfstools to manually increase the size of the smaller preseed disk: https://www.vmware.com/support/developer/vcli/vcli41/doc/reference/vmkfstools.html
The size of the preseed must match the size of the source before one can select it to be used as preseed.

Alternatively, 

• Create a place holder VM with no disks or Operating System or anything on it
• Attach the preseed disk to that VM
• Increase the size of the disk to match the size of the source
• Remove the preseed disk from the VM
• Delete the place holder VM
• Use the disk for preseeding

Affected Versions:

All

Hypervisor:

VMware