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5 vSphere Storage Features You Must Have

• By David Davis
• 06/01/2012

Virtualization needs shared storage for just about every advanced feature. In return, virtualization hypervisors have come up with some amazingly powerful features for optimizing storage. So far, vSphere has offered more than other hypervisors -- and vSphere 5 introduced even more. With your servers' storage virtualized, the hypervisor can now do things that were never before possible (or that you never dreamed possible) with storage.

Here are the top five vSphere storage features you must have to maximize storage functionality, performance and interoperability in your virtual infrastructure.

1. Storage Distributed Resource Scheduler (SDRS): One of the best features introduced with vSphere 5, SDRS does for storage what VMware Distributed Resource Scheduler does for CPU and RAM. In other words, SDRS uses Storage vMotion (svMotion) to automatically move the virtual disks of running virtual machines (VMs) from one datastore to another datastore (it can also be from one LUN to another LUN, or from one SAN to another SAN), with no downtime to the applications in use on those VMs. These svMotions are initiated when SDRS senses that a vSphere datastore either is running low on space or is experiencing latency.

By using SDRS in your vSphere infrastructure, you'll be able to ensure your company's Tier 1 applications receive the storage performance they deserve, and that they don't unexpectedly run out of storage space.

2. Profile-Driven Storage and vSphere API for Storage Awareness (VASA): Also a new feature of vSphere 5, Profile-Driven Storage allows you to define storage capabilities (such as capacity, performance, availability and so on), create VM storage profiles and then match the two up. In other words, you can say that a VM requires storage with a certain capability and then, instead of having to specify a datastore, you can just specify that the VM is on storage with that capability (or perhaps "gold"-level storage).

The capabilities of the storage can be either defined manually by you or, if your storage supports it, learned automatically by using the new VASA.

With storage profiles, you'll be able to run reports to see if your VMs are compliant with the level of storage you specified for each VM when it was deployed. You'll save time by not having to coordinate storage capabilities with the storage admin for every VM deployed.

3. vSphere API for Array Integration (VAAI): VAAI was introduced with vSphere 4.1 and, if your array supports it, allows vSphere and your array to work together to accomplish virtualization storage tasks faster than ever. For example, if a snapshot is initiated, the processing for that task can be offloaded to the array, freeing up your ESXi hosts instead of bogging them down with storage tasks. Other tasks that VAAI can offload to the array are the reservation of space in the Virtual Machine File System (VMFS), file cloning and creation of new VM disk files.

Make sure your storage array supports VAAI, and that vSphere is working with that array so storage functions are faster and more efficient than ever before.

4. vStorage API for Data Protection (VADP): VADP is used by backup tools to offload backup of VMs, eliminating the need for backup agents, downtime during backups and painful backup windows. Additionally, change block tracking (CBT), as part of VADP, provides incremental backup of the VM disk files.

Together, VADP and CBT have made backup, recovery, replication and disaster recovery of virtual infrastructures easier and more efficient than ever before.

5. Storage Views and Maps: vSphere infrastructure maps show VM/host/datastore relationships, but storage views are even more powerful. The vSphere storage views tab shows both reports and maps that also diagram NAS mountpoints, SCSI paths, SCSI LUNs, SCSI adaptors and SCSI targets. When it comes to understanding the complex storage configurations in vSphere, there's no better source of information. As a bonus, don't forget about the new VMFS 5 in vSphere 5. Its improved scalability and feature set are what makes the newest vSphere 5 storage features possible.