The Best Kept Secret in NetApp Data ONTAP 8.3

By on 03/20/2015.

One of the biggest obstacles in storage management to-date has always been what I’ll label as “agility,” or the ability to move data around very quickly without interrupting service.  This has been a stickling point for as long as I can remember.

For NetApp customers, that ends NOW.

There are several new features of clustered Data ONTAP 8.3 from NetApp that haven’t been widely talked about thus far.  These features are collectively known as On-Demand data management and include:

  • Single-File Move on Demand (SFMoD)
  • Single-File Copy/Clone on Demand (SFCoD)
  • Single-File Restore on Demand (SFRoD)

These features have an entire framework supporting them in cDOT. When an operation is triggered, data access at the destination begins immediately, while in the background cDOT is copying or moving the data from source to destination.  The commands are not something that can directly invoked, rather other operations can take advantage of them. This technology is heavily leveraged with our VMware Virtual Volumes integration, for example, but is not limited to that.

Let’s put this in motion and take a look at an example …

When the policy is changed for a VVol object resulting in it needing to move from one volume to another, even across controllers, the On-Demand engine is used.  This non-disruptively moves data access from the source to the destination, triggering a rebind if necessary, instantly.  Writes are being done at the new destination and, while the cluster is copying data from the original source, reads are redirected across the cluster network back to the original.

You can see this working in action using LUNs as well.  LUN move operations, another new feature of cDOT 8.3, take advantage of this mechanism to non-disruptively migrate LUNs across volumes.  Triggering a “lun move start” operation.

Here is an existing LUN. Note that it is currently hosted on volume “iscsi1”:

"lun show" command in Data ONTAP 8.3

“lun show” command in Data ONTAP 8.3

Our LUN contains a VMFS file system and a single virtual machine:

VMware vSphere Web client VM Related Objects

VMware vSphere Web client VM Related Objects

We can see the LUN path in the details provided by the NetApp VASA Provider:

LUN Details in vSphere Web client provided by NetApp VSC/VASA

LUN Details in vSphere Web client provided by NetApp VSC/VASA

Start the move to a new volume, “iscsi2”:


Monitor the progress:


Finally, verify that it has moved:


And our LUN details in vCenter have been updated as well:


Using these features empower storage administrators to do even more operations without storage consumers even knowing what’s happening.  In conjunction with the policy-based management features of VMware Virtual Volumes, we can move virtual machine data around in the cluster quickly, non-disruptively, and easily so that it is utilizing the resources that are most appropriate for the needs of the application.  No more wasted resources, no more changing application requirements stranding data on the wrong storage.

Andrew Sullivan
Andrew has worked in the information technology industry for over 10 years, with a rich history of database development, DevOps experience, and virtualization. He is currently focused on storage and virtualization automation, and driving simplicity into everyday workflows.