Content Library arrived in vSphere 6.0 as a storage container for virtual machine templates, as well as scripts, text files, and ISO images. The idea is to have an efficient and centralized method to manage important content required in a vSphere environment. Instead of mounting a share to each ESXi host to distribute these items, Content Library solves that by sharing library items between vCenter Servers. Sharing content in this manner allows for virtual machine templates, ISOs, or appliances to be deployed directly from a Content Library.
Content Library uses two types of libraries; Local and Subscribed. A Local library is used to store items in a single vCenter Server instance. The Local library allows for items to be stored locally to the vCenter Server. Local libraries can be set to Publish their content so other vCenter Servers can then subscribe to the local library to fetch items needed. A Subscribed library is one that subscribes to the Local Publisher library on another vCenter Server instance. The advantage of the Subscribed library is that you can choose to download all of the content items immediately after the library is created or only download items as needed to save storage space at the Subscriber side.
The Evolution of Content Library
When introduced in vSphere 6.0, this was just the beginning for Content Library. Item types allowed in vSphere 6.0 for Content Library were limited to OVF templates, ISOs, scripts, and text files. When adding Virtual Machine templates (vmtx) to Content Library they were converted to OVF templates to be stored as Content Library in vSphere 6.0 did not yet support VM Templates.
Content Library in vSphere 6.5 added a few minor enhancements. Support for the HTML5 version of the vSphere Client gave customers a consistent look and feel when using this newer client. Support for mounting ISOs from Libraries, updating of existing templates, and Guest Customization when deploying a VM from an OVF template was also introduced for Content Library. Below is an example view of Content Library in vSphere 6.5 showing the libraries listed, along with Summary, Templates, and Other Type (file types) tabs to quickly find items.
Today in vSphere 6.7, Content Library has evolved once again. VM Templates are able to be synchronized to other Content Libraries via the Publish feature. The publishing action from the local library will sync the VM template to the selected Subscriber Libraries. VMTX files are no longer converted to OVF to be stored within Content Library. This allows the ability to distribute content across vCenter Servers to avoid recreating VM template configurations on the other end. We can see below that Content Library has not changed much visually from vSphere 6.5 to vSphere 6.7, although new features are introduced with each release.
Closing
Content Library has come a long way since its start in vSphere 6.0 and continues to evolve with each vSphere release. To learn more and stay tuned about additional Content Library information, please visit the below resources:
