You create a subscribed library to subscribe to a published library. Subscribed libraries are content libraries whose content is connected to the content of a published local library. You cannot add content to a subscribed library, you can only synchronize the content of the subscribed library with the content of the published library.

You can create the subscribed library in the same vCenter Server instance where the published library is, or in a different vCenter Server system. When you create a subscribed library, you can download all the contents of the published library immediately after the subscribed library is created. Alternatively, you can download only the metadata for the items from the published library and later download the full content of only those items that you need.

To ensure the contents of a subscribed library are up-to-date, the subscribed library automatically synchronizes to the source published library at regular intervals. You can also manually synchronize a single item or an entire subscribed library.

For information about synchronizing an entire subscribed library, see Synchronize a Subscribed Content Library.

For information about synchronizing a library item in a subscribed library, see Synchronize a Library Item in a Subscribed Library.

For information about managing subscriptions and publishing content to a subscriber, see Managing a Publisher Local Library.

Download Methods for Synchronization

When you create a subscribed library, you can use the option to download content from the source published library immediately or only when needed to manage your storage space.
  • When you synchronize a subscribed library that is configured to download all the contents of the published library immediately, the process synchronizes both the item metadata and the item contents. During synchronisation, the library items that are new for the subscribed library are fully downloaded to the subscribed library storage. If some items are deleted from the published library, their contents remain at the storage location of your subscribed library, and you have to manually delete them.
  • When you synchronize a subscribed library that is configured to download contents only when needed, the process synchronizes only the metadata for the library items from the published library, and does not download the contents of the items, which saves storage space. If you need to use a library item, you need to synchronize that item. Synchronizing a library item downloads the full content of that item to your storage. When you no longer need the item, you can delete the item contents to free storage space.
You can take advantage of optimized transfer speed for synchronization between a published and a subscribed library under certain circumstances.
  • If a published and a subscribed library belong to vCenter Server systems that are in the same vCenter Single Sign-On domain, and both libraries use datastores as backing storage, transfer speed for synchronization is faster. The transfer speed optimization is made possible if the libraries can store their contents to datastores managed by ESXi hosts that are directly connected to each other. Therefore, the synchronization between the libraries is handled by a direct ESXi host to ESXi host transfer.
  • If the datastores have VMware vSphere Storage APIs - Array Integration (VAAI) enabled, the library content synchronization between the published and the subscribed library is further optimized. In this case, the contents are synchronized by a direct datastore to datastore transfer.

The supported download methods depend on the source library. See the table below for more information.

Table 1. Source Objects to Which You Can Subscribe by Creating a Subscribed Library in the vSphere Client
Source Object Download library content immediately Download library content when needed
A library running in a vCenter Server 6.x instance Supported Supported
A catalog running in a vCloud Director 5.5 and later instance Supported Not supported
A third-party library Supported for third-party libraries that require authentication, if the username of the third-party library is vcsp. If the username of the source third-party library is different than vcsp, you can subscribe to it by using the VMware vCloud Suite API. Supported for third-party libraries that require authentication, if the username of the third-party library is vcsp. If the username of the source third-party library is different than vcsp, you can subscribe to it by using the VMware vCloud Suite API.