Tag Archives: QoS


Come full circle with NexGen Storage


NexGen is storage that’s not just intended for virtualization, they support Citrix, VMware and Hyper-V,  but general use storage as well.  The founders of Lefthand, John Spiers and Kelly Long came up with NexGen.  Eventually acquired by Fusion I/O and onto SanDisk, as of January 2015, they are now their own entity once more. (insert clapping!)

The main difference between NexGen and other storage vendors with acceleration is that the appliance uses PCIe Flash. Using the memory bus brings in lower latency and higher bandwidth than SSDs.  You can scale out simple by adding PCIe flash devices and interconnects are SAS/SATA between trays.  Flash is only for write cache and RAM is used for read cache.


There are five QoS policies for performance with 3 categories:  mission critical, business critical and non-critical.  Below shows the prioritized active cache for each setting:




 You can map these policies directly to VMware’s storage policies per VVOL which brings simplicity with management.  In the demo, NexGen shows how you can create containers, map them to a policy and deploy VMs to the selected VVOL/policy.

 VVOL Demo

 As far as vSphere, the NexGen appliance is designed to converge infrastructure management to capitalize on the newer vSphere 6 capabilities. They are a VASA 2.0 provider, allow QoS on the I/O type now with NexGen ioControl 3.5.  That means they are the first and only NVMe ready with VM-level QoS.  These enhancements do depend on VVOLS but with it you can change the data-path rather than a SvMotion.

NexGen does provide a vCenter plugin and a web-based interface.
Along with that there is a REST API you can call with PowerCLI or JSON .
With vCenter integration, you can get information like per VMDK storage metrics, IOPS, queue depth, through-put and block-size. SAN metrics are saved for a year on each VM and you can correlate the entire data path for performance statistics gathering.


 At Virtualization Field Day 5,they showed how you can change policies on the fly and it will immediately impact the VM. Bringing up the point that you don’t have to do a storage vMotion to faster storage but just change the policy on the VVOL, seems pretty slick.

NexGen Storage QoS Manager for VMware from Stephen Foskett on Vimeo.


Disclosure: I learned about NexGen Storage at Virtualization Field Day 5. All travel and incidental expenses for attending Virtualization Field Day 5 were paid for by Gestalt IT. This was the only compensation provided and it did not influence the content of this post.