FlexApp Using VHDs vs VMDKs


ProfileUnity’s FlexApp and ProfileDisk technologies offer the flexibility to choose between using VHDs or VMDKs. With these technologies applications, user profiles, and user data are stored inside a virtual hard disk (VHD) on the network or a VMware virtual machine disk (VMDK) on storage visible to the ESXi host. A VHD looks like a local file system but can be mounted from anywhere on the network that we want to host our applications. VMDKs also look like a local file system but are mounted from the storage visible to the ESXi host where the desktop is running. Using a virtual disk has a number of benefits including IOPS reductions, file system compression, and application portability.

At Liquidware, a question we frequently get asked is, “Should I use a VHD or a VMDK?” The answer is that it depends. Not all features in these technologies are supported on both platforms.

Feature Comparison Chart

Use this ProfileUnity feature comparison chart to help guide you in deciding which is the best storage option per feature for your environment.

Feature VHD VMDK/FlexDisk
ProfileDisk Supported Supported
ProfileDisk RDSH Supported
(starting in v6.7.0)
Not Supported
FlexApp: Computer-level Supported Supported
(starting in v6.7.0)
FlexApp: User-level Supported Supported
FlexApp: User Group-level Supported Supported
FlexApp: Attach Now Not Supported Supported
FlexApp: Click-to-Layer (version 6.7.0 and higher) Supported Not Supported
FlexApp: Click-to-Layer for Published Apps (version 6.7.0 and higher) Supported Not Supported
FlexApp: Cached Mode Application Deployment Supported Not Supported
FlexApp: Use of Other ProfileUnity UEM Filters Supported Not Supported
FlexApp: Cloud Storage, AWS S3, Google GCS and Azure Blob Supported Not Supported

Deployment Differences

One of the most powerful features of ProfileUnity is the User Environment Management filters that can be leveraged during the assignment of FlexApp Layers. Note that filters apply to VHD-based FlexApp packages/layers but not to VMDK-based FlexApp layers. VMDK-based FlexApp layers currently support user, group and basic machine assignments. The primary reason for the difference in VHD vs. VDMK package types centers on architecture. The ProfileUnity Configuration INI-based workflow does not apply to the VMDK-based assignments controlled by vCenter.