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Managing storage in large vSphere environments can definitely be a challenge. If you're unable to use Storage Distributed Resource Scheduler to solve storage management problems in you environment, then your job is even harder. With VMware Virtual Volumes a lot of the work is done for you. Learn more about the benefits of VVOLs, the requirements that must be met to use the VMware VVOL feature, the key components of VVOLs, how best to manage them and what to consider before implementation with these five quick tips.
Advantages of VVOLs
With VVOLs, admins can allocate and manage storage on a per-VM basis, whereas traditional provisioning involves manually allocating storage as a logical unit number (LUN) with multiple VMs. The problem with the traditional approach is that the allocation is done in advance, so you're risking either idle storage capacity or the LUN running out of space. Another benefit of the VMware VVOL feature is that you can have it automatically provision storage, which eases the management burden. You can also organize storage into different classes across multiple systems, including Fibre Channel, Network File System (NFS) and iSCSI. In other words, mission critical workloads can be serviced by faster systems and less critical workloads can be serviced by slower systems. Ultimately, VVOLs allow administrators to use storage more efficiently across their environments.
VMware VVOL requirements
In order to use VMware VVOL technology, there are specific requirements that must be met. First, you need to have vSphere 6.0 or later. Next, check VMware's compatibility guide to ensure that your storage array supports VVOLs. Currently, there are 20 vendors who partner with VMware to build VVOLs into their storage arrays, but you may need to perform a firmware update to use this feature. If you're already using the vSphere APIs for Storage Awareness (VASA) provider for storage management, remember to upgrade it before deploying VVOLs to achieve better integration between vCenter Server and the storage array. Because several upgrades are required to use VVOLs, it's important to have a plan of execution and to thoroughly test each upgrade as you go.
VMware VVOL components
VVOLs, storage containers, VASA provider plug-ins and protocol endpoints all come together to make up the VMware VVOL architecture. These four elements are very different, but they're all related. The VVOLs themselves represent different object types: Config-VVOL, Memory-VVOL, Data-VVOL, Swap-VVOL and Other-VVOL. The objects are then grouped based on similar policies or services and are kept in storage containers, which act as LUNs in this environment. Plug-ins from storage vendors allow the ESXi hosts and vCenter Server to recognize storage subsystem capabilities like topology and capacity, but they must adhere to VASA version 2.0 or later. Finally, data transport between the ESXi hosts and storage subsystems is provided by protocol endpoints, which are employed by vSphere and support Fibre Channel, Fibre Channel over Ethernet, NFS v3 and iSCSI protocols.
Management options for VVOLs
Administrators have a choice between using the vSphere Web Client or the ESXi command-line interface to deploy and manage VVOLs. When using vSphere Web Client, consider taking at least some of the following steps before enabling the VMware VVOL feature: Synchronize the time between vCenter Server instances and ESXi hosts, import VASA provider plug-ins, create a virtual data store for VVOLs and mount it onto multiple hosts. After enabling VVOLs, you can set VM storage policies and then deploy VMs onto data stores. You also have the ability to migrate VMs that are powered on or off from VMware Virtual Machine File System or NFS data stores to VMware VVOL data stores.
VMware VVOL considerations
While the VMware VVOL feature can ease storage management issues, administrators will still have their hands full with its implementation. Besides meeting general requirements to deploy VVOLs in production, it's important to examine how storage is provisioned in your environment to ensure those practices will still be effective when using VVOLs. Also, be sure to review capacity planning strategies. The impact on application performance and reliability is a key factor to consider when incorporating VMware VVOL technology. Another thing to keep in mind is that storage vendors still need to offer key storage services to VVOLs to make them more efficient. Once features like data compression, snapshots and cloning are available to VVOLs, the functionality and overall benefits of this feature can be fully realized.
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