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Thomas Rein

Migrate Windows VM with more than 4 Disks from VMware to OVM

Suppose you got an OVA image created on VMware and the VM contains more than 4 Disks
and you have to migrate this machine from VMware to OVM.

As first step you import the OVA into the OVM in the usual way:

Bildschirmfoto 2018-02-02 um 09.43.12

You see the that the appliance was imported successfully, we have 5 disks:

Bildschirmfoto 2018-02-02 um 09.45.25

Now you create your VM from the imported appliance:

Bildschirmfoto 2018-02-02 um 09.47.34

So far so good, lets have a look on our newly created VM:

Bildschirmfoto 2018-02-02 um 09.51.22

All seems good, but if you edit the machine (we want to add a network and give a boot order for the system) you will be surprised:

Bildschirmfoto 2018-02-02 um 10.11.35

Oops, we lost a disk, what happened? You don’t make a mistake, its a restriction on OVM: states that a VM can have only 4 IDE disks in maximum, and if you import your Windows VM its considered as Xen HVM Domain Type, so you can only attach 4 disks to the VM.

And now, how can we solve the problem? Lets first try, if we can boot the system:

Bildschirmfoto 2018-02-02 um 10.25.32

Ok system is up what next? We deinstall all the VMware utilities:

Bildschirmfoto 2018-02-02 um 10.35.40For the next step we download the Oracle VM Server for x86 Windows PV Drivers – for Microsoft Windows x64 (64-bit) from and install them on our Windows Box:

Bildschirmfoto 2018-02-02 um 11.04.28

After a system restart, all disks except the C: drive are gone:

Bildschirmfoto 2018-02-02 um 11.08.51

We shutdown the Windows Box and put the VM into the Xen HVM PV Driver Domain:

Bildschirmfoto 2018-02-02 um 12.07.39

After that we can add our lost disk without any problems:

Bildschirmfoto 2018-02-02 um 12.09.00

Ok lets restart the system look what happens:

Bildschirmfoto 2018-02-02 um 12.16.48

Ok all disks are there, we can now bring them online:

Bildschirmfoto 2018-02-02 um 12.59.29

After a reboot we can see that our drives are used correctly:

ARC3: Archival started
Thread 1 opened at log sequence 4743
Current log# 3 seq# 4743 mem# 0: I:\ORADATA\TESTIDM1\REDO03.LOG
Successful open of redo thread 1




One Comment

  • MississippiMadMan says:

    Since OVM 3.4.6 this is no longer possible. 3.4.6 disables PVM completely.
    I did find a way by modifying the vm.cfg file manually, but I don’t believe Oracle will support it.
    The 5th disk will still not appear in the OVM console eventhough it is attached to the running VM.
    Haven’t uncovered anything with the Xen docs around whether this will be an issue or not, but I’m using it for now.
    (Also, for the record, I’m running a Linux VM and not Windows with a mixture of local virtual disks and physical SAN volumes)

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Thomas Rein
Thomas Rein

Principal Consultant