A resource provider is able to manage instance data associated with virtual compute instances running in the resource provider environment. For example, when provisioning a compute instance, the resource provider can obtain data associated with the compute instance and can store this data, for example, in a data store. The resource provider can act as a centralized repository of such data for some or all instances that are running in the resource provider environment. Entities (e.g., users or other compute instances running in the resource provider environment) can query the resource provider to perform various operations (e.g., read, modify, duplicate) on the data being managed by the resource provider for the various compute instances. Any changes to the data for a compute instance, for example, by a user, the compute instance, or a different compute instance, can be saved by the resource provider and propagated to the compute instance.