Recently I presented a short vBrownbag on the topic of View Composer for Array Integration (VCAI) with a focus on how VCAI benefits Horizon View environments, Storage Protocol choice for Horizon View deployments and how Nutanix leverage’s VCAI to optimize Horizon View Deployments.
The video is available here – View Composer for Array Integration VCAI) & Nutanix
Problem Statement
What is the most suitable storage protocol for a Virtual Desktop (VMware View) environment using Linked Clones?
Assumptions
1. The Storage Array supports NFS native snapshot offload
2. VMware View 5.1 or later
Motivation
1. Minimize recompose (maintenance) window
2. Minimize impact on the storage array and HA/DRS cluster during recompose activities
3. Reduce storage costs where possible
4. Simplify the storage design eg: Number/size of Datastores / Storage Connectivity
5. Reduce the total solution cost eg: Number of Hosts required
Architectural Decision
Use Network File System (NFS)
Justification
1. Using native NFS snapshot (VAAI) offloads the creation of VMs to the array, therefore reducing the compute overhead on the ESXi hosts
2. Native NFS snapshots require much less disk space than traditional linked clones
3. Recomposition times are reduced due to the offloading of the cloning to the array
4. More virtual machines can be supported per NFS datastore compared to VMFS datastores (200+ for NFS compared to max recommended of 140, but it is generally recommended to design for much lower numbers eg: 64 per VMFS)
5. Recompositions/Refresh activities can be performed during business hours, or at Logoff (for Refresh) with minimal impact to the HA/DRS cluster, thus giving more flexibility to maintain the environment
6. Avoid’s potential VMFS locking issues – although this issue is not as important for environments using vSphere 4.1 onward with VAAI compatible arrays
7. When sizing your storage array, less capacity is required. Note: Performance sizing is also critical
8. The cost of a FC Storage Area Network can be avoided
9. Fewer ESXi hosts may be required as the compute overhead of driving cloning has been removed
Implications
1. In the current release, 5.1, View Storage Accelerator (formally Content Based Read Cache or CBRC) is not supported when using Native NFS snapshots (VAAI)
2. Also in the current release 5.1, “Use native NFS snapshots (VAAI) is in “Tech Preview” – This is rumored to change in View 5.2
Alternatives
1. Use VMFS (block) based datastores and have more VMFS datastores – Note: Recompose activity will be driven by the host which adds an overhead to the cluster.