IBM Storage and the Beauty and Benefits of VVols
This post was originally written as a guest post for VMware for VMworld 2015 conference. Read the full blog post [IBM Storage and the Beauty and Benefits of VVol]. The following is an exerpt:
Back in 2012, I had mentioned that VMware was cooking up an exciting new feature called VVol, short for VMware vSphere Virtual Volume.
Officially, the VVol concept was still just a "technology preview" in 2012, to be fleshed out over the next few years through extensive collaboration between VMware and all the major players: IBM, HP, Dell, NetApp and EMC.
In 2013 and 2014, IBM attended VMworld with live demonstrations of VVol support. VMware vSphere v6 was not yet available, but when it was, we assured them, IBM would be one of the first vendors with support!
When vSphere v6 was finally made available earlier this year, [only four vendors support VVols on Day 1 of vSphere 6 GA]! Keeping true to its promises, IBM was indeed one of them.
To understand why VVol is such a game-changer, you have to understand a major problem with VMware version 4 and version 5, namely their Virtual Machine File System, or [VMFS].
Here is a picture to help illustrate:
On the left, we see that VMFS datastore is a set of LUNs from the storage admin perspective, and a set of VMDK and related files from the vCenter admin perspective.
If there was a storage-related problem, such as bandwidth performance or latency, how would the two admins communicate to perform troubleshooting? For many disk systems, it is not obvious which VMDK file sits on which LUN.
There are also a variety of hardware capabilities that work at the LUN level, such as snapshots, clones or remote distance mirroring, and this would apply to all the VMDK files in the data store across the set of LUNs, which may not be what you want.
There are two ways to address this in vSphere v4 and v5:
On the right side of the picture, using VMware v6, vCenter admins can now allocate VVols, which are mapped to specific "VVol Storage Containers" on specific storage systems. The storage admin knows exactly which VVol is in which container, so they can now communicate and collaborate on troubleshooting!
The vSphere ESXi host communicates to storage arrays via a new "virtual LUN id" called a "Protocol Endpoint". This is to allow FCP, iSCSI and FCoE traffic to flow correctly through SAN or LAN switches. For NFS, the Protocol Endpoint represents a "virtual mount point", so that traffic can be routed through LAN switches correctly.
Storage Policies can help determine which attributes or characteristics you want for your VVol. For example, you may want your VVol to be on a storage container that supports snapshots at the hardware level. The vCenter server can be aware of which storage arrays, and which storage containers in those arrays, through the VMware API for Storage Awareness, or VASA.
Different storage manufactures can implement their VASA provider in different ways. IBM has opted to have a single VASA provider for all of its supported devices, so as to provide consistent client experience. When you purchase any VVol-supported storage system from IBM, you are entitled to download the IBM VASA provider at no additional charge!
Initially, the IBM VASA provider will focus on IBM XIV Storage System, an ideal platform for your VVol needs. The XIV is a grid-based storage system, utilizing unique algorithms that give optimal data placement for every LUN or VVol created, and virtually guarantees there will be no hot spots. The XIV provides an impressive selection of Enterprise-class features, including snapshot, mirroring, thin provisioning, real-time compression, data-at-rest encryption, performance monitoring, multi-tenancy and data migration capabilities.
With the XIV 11.6 firmware level, you can define up to 12,000 VVols across one or more storage containers in a single XIV system. For more details, see IBM Redbook [Enabling VMware Virtual Volumes with IBM XIV Storage System].
Let me give some real world examples from Paul Braren, an IBM XIV and FlashSystem Storage Technical Advisor from Connecticut, who has been working directly with clients over the past five years:
In addition to XIV, all of IBM's Spectrum Virtualize products also support VVolLs, including SAN Volume Controller, Storwize including the Storwize in VersaStack, and FLashSystem V9000.
I am not in San Francisco this week for VMworld, but lots of my IBM colleagues are, so please, stop by the IBM booth and tell them I sent you!