Virtualization Articles and Resources

Rapid Cloning Utility v3.0 Frequently Asked Questions (FAQ)


Where do I get the software?

The Rapid Cloning Utility is a free and supported application that can be downloaded from the now site.

Where can I find demonstrations of the RCU 3.0 features?

I heard there was a series on Tech Target regarding RCU 3.0.  Do you have links?

Do I need FlexClone to provision only?

No. FlexClone is no  longer a required license for RCU.

Do I need FlexClone  to clone?

Yes. FlexClone is required for cloning any object in  RCU.

Does RCU 3.0 support Datastores mounted on qtrees?

Yes, the following cloning operations are supported with qtrees:

  • Cloning from a qtree to a qtree on the same volume.
  • Cloning from a qtree to a qtree on a different volume.
  • Cloning from a volume to a qtree within the same volume.
  • Cloning from a volume to a qtree on different volumes.
  • Cloning from a qtree to the volume containing the qtree.
  • Cloning from a qtree to a different volume.
  • Cloning from local storage to qtrees.

How do quotas effect ESX?

Quotas will be enforced when they are mounted to ESX hosts. If no quota has been created for the qtree, the size of the datastore will be based on the size of the volume that contains it. It is important to note that qtrees with quotas do not offer the space savings you would see with file level flexclones within the volume.

Does RCU 3.0 support vfilers (MultiStore)?

Yes.  Please note that Data OnTap 7.3.3 is required for vfiler support.

How do I use vfilers with RCU 3.0?

The individual vfiler should be added (just like physical controllers) to RCU in the Controllers section.

What features are available when using vfilers?

  • VMFS/ iSCSI Datastore provisioning
  • Virtual Machine cloning in existing NFS Datastores
  • Virtual Machine cloning in new and existing VMFS/iSCSI Datastores
  • Datastore Resize of VMFS is supported
  • Datastore Destroy

What features wont work when using vfilers?

  • Datastore Resize on NFS is not supported  in the vfiler context
  • NFS Datastore provisioning is not supported in the vfiler context
  • VMFS/FCP Datastore provisioning is not supported in the vfiler context

What version of vCenter is required for RCU 3.0?

vCenter 4.0.

What version of ESX is required for RCU 3.0?

ESX 3.5, ESXi 3.5, ESX 4.0 and ESXi 4.0 are all supported when managed by a vCenter 4.0 server.
Note: to grow a VMFS datastore, it must be mounted on an ESX/ESXi 4.0 hosts.

Does RCU 3.0 work with VMware View 4.0?


Does RCU 3.0 work with VMware View 3.0?

No.  To use VMware View 3.0, please use RCU 2.1.

Does the re-deploy feature in RCU 3.0 completely replace the disks on the target VM(s)?

Yes.  Please note that the re-deploy feature is a 'rip and replace' of the virtual hard drives on the target virtual machines.

Does the RCU 3.0 set the best pathing policy for each datastore durning provisioning and cloning?

Yes.  This is true for NFS, iSCSI and FCP on both ESX/ESXi 3.5 and ESX/ESXi 4.0.

Does RCU provide a feature to allow the guest host name to match the VM name when using sysprep based answer file?

Yes.  Please see this video for a demonstration.

Can RCU clone the nvram file (emulated BIOS settings)?

Yes.  The default is not to though.  To enable nvram cloning, please add the following entry:

<entry key="default.create.copyNvramFile" value="true"/>

to the following file:

<install dir>/conf/rcuPreferences.xml

Why does RCU fail to provision an NFS datastore?

The most likely reason is that there is not a vmkernel interface on the same subnet as a NetApp controller interface.  This is a requirement of RCU 3.0.  Another common issue is that RCU can not resolve the host name of either the vmkernel interface or the controller interface.  If neither of these is the cause of your issue, please open a ticket with NetApp Global Support.

Is RCU 3.0 available for 64-bit operating systems?

Yes.  There are two separate setup files; one for 32-bit OSes and one for 64-bit OSes.  Please note this refers to the OS RCU will be running on, not the guest OS.  Either version of the RCU 3.0 can handle both 32-bit and 64-bit guest operating systems.

I cloned a VM with both IDE based virtual hard drives and SCSI virtual hard drives and the resulting VM will not boot, is this supported?

  • Cloning VMs with all hard drives attached via VirtualIDEController(s) is supported by RCU 3.0
  • Cloning VMs with all hard drives attached via VirtualSCSIController(s) is supported by RCU 3.0
  • Cloning VMs with a mix of VirtualIDEController attached hard drives and VirtualSCSIController hard drives is not supported.

RCU will only allow my to create X number of clones of my VM that is attached to a Distributed Switch. Where does RCU get this number?

RCU determines this number (X) based on the number of free ports on the Distributed Switch.  This is becuase ports are allocated as nics are added to the distributed switch, not when VMs are powered on (as  on standard vSwitches).

How do I use Data OnTap Role Based Access in RCU 3.0?

See this document.

How do I use vCenter Role Based Access Controls in RCU 3.0?

See this document.

Where do I find information on the API?

In Appendix C of the Installation and Administration Guide.

Examples are provided and explained in the Rapid Cloning Utility v3.0 API Examples document.

Which feature of FlexClone is used?

  • File level FlexClone is used to create clones of virtual disks (vmdk files) attached to a VM
  • LUN level FlexClone is used to create clones of vmfs datastores
  • Volume level FlexClone is used to create clones of nfs datastores

Does RCU use lun clone?

RCU does not use the snapshot based lun clone (that comes free with block protocols).

How to I maximize space savings and speed when using RCU?

  • The closer the source vmdk file is to the destination, the faster and more dense the result will be.
  • Here is the logic for the first copy on NFS:
    • Source and Destination are the same Datastore (and therefore volume) we use file level FlexClone.
    • Source and Destination are different, but on the same controller we use controller based copy (controller offload).
    • Source and Destination are on different controllers, we use native vCenter clone (no controller offload).

Is there any way to change the behavior of RCU?

There is a preferences file in the conf directory called rcuPreferences.xml.  The knowledge base article kb56796 contains the valid entries and descriptions for this file.

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You mention in the FAQ above that 7.3.3 is required for vfiler support - does this mean it is also supported in 8.0 7-mode?




Sorry, vfiler support is only for 7.3.3 at this time.  8.x (7 mode) is planned for the near future.

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