With Writable Volumes, you can configure per-user volumes where users can install and configure their own applications and keep the data that is specific to their profile. Because you assign a Writable Volume to a specific user, the data that it stores migrates with the user to different machines.
A Writable Volume is an empty VMDK or VHD file that you assign to a specific user. It mounts to the VM when the user authenticates to the desktop. You can assign many Writable Volumes to a user, but you can attach only one Writable Volume at a time.
Examples of the data that a Writable Volume can contain are application settings, user profile, licensing information, configuration files, user-installed applications, and others.
With the latest version of App Volumes, you can also specify exclusions that are targeted for writable volumes. These exclusions do not affect AppStacks or system volumes. For more information, see Writable Volumes Exclusions.
Using Writable Volumes with User Environment Management Solutions
You can use Writable Volumes to complement a user environment management solution, for example VMware User Environment Manager. Such solutions can manage data in Writable Volumes at a more granular level and enforce policies based on different conditions or events by providing contextual rules. With ,Writable Volumes you can use containers for local user profile delivery across systems.
Using Writable Volumes with Non-Persistent Virtual Desktops
On a non-persistent virtual desktop environment, all applications that the user installs are removed after the user logs out of the desktop. Writable Volumes store the applications and settings of users and make user-specific data persistent and portable across non-persistent virtual desktops. This way, you can address use cases, such as providing development and test machines for users to install custom applications on non-persistent virtual desktops. You must reboot the desktop after you remove a Writable Volume.
Storage Configuration with Writable Volumes
When designing your environment for Writable Volumes, consider that a Writable Volume requires both read and write I/O. The input output operations per second (IOPS) for a Writable Volume might vary for each user depending on the users consume their data. IOPS might also vary depending on the type of data that the users are allowed to store on their Writable Volume.
You can manage the number of Writable Volumes that can be configured on a single storage LUN by monitoring how the users access their Writable Volumes.
Writable Volumes Exclusions
Using the Writable Volumes exclusions feature, you can exclude specific locations of user Writable Volumes, such as file paths or registry keys, from being overwritten. Use this feature only if you are an IT administrator or an advanced App Volumes administrator. See Writable Volume Exclusions for more information.