EFI Compatibility Error - Vcenter VM Migrating to AWS Using Server Migration Service

[PEZUES]

I am trying to achieve some redundancy by having some of my VM's imported to EC2. I am currently trying to do this with a CentOS VM that is booting with EFI.

Problem is, AWS Server Migration Service only imports VM's that are booting with MBR.

Does anyone here know a way to get around this issue so I can migrate VM's that have an EFI partition? Is rebuilding the VM's the only way? Thanks in advance.

[dariusd · Accepted solution]

The AWS Server Migration Service User Guide​ suggests that the limitation is not in the import tool but is actually in EC2 itself:

Booting

• UEFI/EFI boot partitions are supported only for Windows boot volumes with VHDX as the image format. Otherwise, a VM's boot volume must use Master Boot Record (MBR) partitions. In either case, boot volume cannot exceed 2 TiB (uncompressed) due to MBR limitations.

  :smileyinfo: Note

  When AWS detects a Windows GPT boot volume with an UEFI boot partition, it converts it on-the-fly to an MBR boot volume with a BIOS boot partition. This is because EC2 does not directly support GPT boot volumes.

  If EC2 doesn't support GPT boot (and hence does not support EFI boot), you will have no choice but to switch to BIOS boot.  I am aware of the existence of tools to convert MBR/BIOS boot systems to GPT/EFI boot, but not the other way... so unfortunately you might end up having to rebuild the VM.

  You might be able to short-cut the rebuild process by installing a BIOS CentOS VM alongside the existing EFI VM, then seeing if you can export the list of installed packages from yum/rpm on the EFI VM and apply that list of packages to the BIOS VM to get the software into a comparable state, diff the filesystem listings, scp/rsync over stuff that you need to keep (being careful to avoid clobbering BIOS boot stuff!), etc.  Maybe Redhat/CentOS has something to automate such a system transfer... I don't know, but it sounds like a reasonable tool that someone might have written.

  If you do discover anything interesting along the way, we'd love to hear about it.

  Thanks,

  --

  Darius

[PEZUES]

I will attempt a rebuild with BIOS selected. Thank you for your response!