Corrigi o primeiro erro ao fazer isso:
D:\Program Files\Oracle\VirtualBox>vboxmanage internalcommands sethduuid "D:\Virtual Machines\VirtualBox\UNIX Machines\Server Name\ExtraHDD.vdi" "7ee23ee6-2dd9-4ae0-ae1c-c5ee532fab95"
UUID changed to: 7ee23ee6-2dd9-4ae0-ae1c-c5ee532fab95
E agora só tenho mais um erro.
D:\Program Files\Oracle\VirtualBox>VBoxManage snapshot "Server Name" delete "Extra HDD Added (no longer available)"
VBoxManage.exe: error: Code E_FAIL (0x80004005) - Unspecified error (extended info not available)
VBoxManage.exe: error: Context: "LockMachine(a->session, LockType_Shared)" at line 331 of file VBoxManageSnapshot.cpp
Última atualização:
Alterei o nome do instantâneo (perdi um {
no nome) e agora recebo um erro ainda pior:
D:\Program Files\Oracle\VirtualBox>VBoxManage snapshot "Server Name" delete "Extra HDD Added (no longer available)"
0%...
Progress state: E_FAIL
VBoxManage.exe: error: Snapshot operation failed
VBoxManage.exe: error: Could not open the medium 'D:\Virtual Machines\VirtualBox\UNIX Machines\Server Name\Snapshots/{e3ef3706-6882-4404-8478-f085ca9f3b1e}.vdi'.
VBoxManage.exe: error: VDI: error reading pre-header in 'D:\Virtual Machines\VirtualBox\UNIX Machines\Server Name\Snapshots/{e3ef3706-6882-4404-8478-f085ca9f3b1e}.vdi' (VERR_EOF).
VBoxManage.exe: error: VD: error VERR_VD_VDI_INVALID_HEADER opening image file 'D:\Virtual Machines\VirtualBox\UNIX Machines\Server Name\Snapshots/{e3ef3706-6882-4404-8478-f085ca9f3b1e}.vdi' (VERR_VD_VDI_INVALID_HEADER)
VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component MediumWrap, interface IMedium
VBoxManage.exe: error: Context: "enum RTEXITCODE __cdecl handleSnapshot(struct HandlerArg *)" at line 532 of file VBoxManageSnapshot.cpp
Infelizmente, não há solução (que eu possa ver) no Google.