VMware Array Integration is Right Here, Right Now
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Virtualization of servers and desktops places a massive strain on traditional storage environments. This is mostly due to the “missing link” of communication between storage arrays and hypervisors. The array needs information about the virtual environment to function properly, and hypervisor could benefit from array features. This is where integration technologies like VAAI come into play, and why these technologies are increasingly important to customers.
Virtual servers and desktops place a unique strain on storage devices. They randomize I/O and increase the amount of traffic on each interface. The hypervisor also interferes with the use of valuable storage features like snapshots, replication, and thin provisioning.
This is the reason that VMware introduced their vStorage API for Array Integration (VAAI) with vSphere 4.1 and the API for Storage Awareness (VASA) in vSphere 5. In both cases, the integration flows in both directions: From the hypervisor to the storage and from the storage to the hypervisor.
The 3 functions of VAAI have become integral parts of modern virtual infrastructure. Many storage arrays have excellent thin provisioning capabilities, but needed better communication about which blocks were no longer required. VAAI exposes this information to supported storage arrays thanks to the Block Zeroing primitive. Arrays also do an excellent job moving data
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around, so the VAAI Full Copy primitive allows the hypervisor to offload cloning and mirroring of data.
Since hypervisors are built to share storage resources between clustered servers, a better mechanism was needed to lock and unlock locked storage. This led to the creation of the VAAI primitive known as Hardware Assisted Locking or Atomic Test and Set, which drastically accelerates I/O operations when resources are shared. This type of hypervisor-driven storage functionality is likely to continue to grow in importance in the future, with storage arrays adapting to the demands of virtual data centers.
End-users have been very enthusiastic about the impact of this sort of array integration with the hypervisor. It allows them to take better at vantage of the advanced features of their storage arrays, and results in dramatic performance improvements. Full Copy, for example, can improve the performance of cloning operations by order of magnitude or more, and Hardware Assisted Locking dramatically improves performance of active virtual machine clusters.
If you would like to learn more about these VMware integration features, I suggest you join me on February 15 for a webinar on the subject. Click here to Register. I will be discussing the topic of storage integration for virtual machines with Lucas Nguyen of VMware and Chris Saul of IBM. I hope you can join us. You may also be interested in my recent blog post outlining all of the VAAI primitives in detail.
Posted
Fri, Jan 27 2012 6:48 AM
by
Stephen