Hey there! In our last post we have seen the basic platform features that were introduced in vSphere 6, now let’s see the vCenter Server enhancements and changes in version 6 like Architectural changes, Certificate Management, vMotion enhancements, vSphere Web Client.
Windows vs VCSA
With version 6, VCSA is now on par with the Windows based installation of the vCenter Server, the scalability features are just the same with no compromise on performance. The only external DB that VCSA now supports is Oracle and SQL server is not supported.
vCenter in version 6 has undergone many architectural changes with the introduction of a new component called PSC. This gives us option to deploy vCenter in two ways; Embedded and Centralized. Embedded model deploy vCenter and PSC on the same machine while Centralized deploy PSC and vCenter Server instances on different machines.
vCenter Services like vCenter Inventory Service, vSphere Web Client and Auto Deploy are installed with vCenter Server and they can no longer be installed separately. Only Update Manager is the standalone component that requires a Windows installation.
Platform Service Controller
PSC is a component built into vCenter Server and combines common services that are used across vCloud Suite; this includes services such as Single Sign-On, Licensing and Certificate Management. Having a sepearate component for these services makes the vCenter installs and upgrades. PSC is the first component that is installed or upgraded.
An infrastructure with many PSCs use built-in replication which replicates licensing information, roles and permissions to other PSCs. It is not possible to switch models after deployment and also cannot change connections between PSCs after installation
Enhanced Linked Mode
In earlier versions of vCenter Servers, linked mode was only restricted to Windows based installation of VC. From vSphere 6, due to the fact that PSCs replicate all the traditionally needed information for linked mode, it is now possible to implement linked mode for any installation of vCenter as long as all the vCenters are part of the same SSO domain.
When a vCenter Server service or a Inventory Service is registered with the SSO, solution users are created and these solution users act as end points for certificates instead of services reducing the number of certificates needed to manage. Two new components are introduced in vSphere 6.
VMCA – VMware Certificate Authority is a root CA that issues signed certificates to all vSphere components through solution users. This avoids the need for self signed certificates used in earlier versions. VMCA can also be configured as subordinate CA if an enterprise already has a enterprise root CA.
VECS – VMware Endpoint Certificate Services is a certificate store that stores all the certificates including third party certificates and private keys for the vCenter Server and services. ESXi cerificates are still stored locally on the host but can be provisioned by the VMCA.
VMCA can be deployed as Root CA or a Issuer CA. When deployed as a Root CA, a self signed certificte is generated and this is capable of issuing other certificates.
vMotion in version 6 can do many great things. vMotion is now possible across virtual switches, across vCenter Servers be it Windows based or VCSA and across long distances of up to 150ms Round trip time. For the vMotion across vCenter servers, both the vCs must be on version 6 and this cannot be used as a upgrade path. There is no loss of historical data when cross vCenter vMotion is performed. Both the VCs should be joined to same SSO and atleast 250Mbps bandwidth is required for each vMotion.
For cross vSwitch vMotion, the source and destination port groups must share the same L2 netowrk connectivity. IP address within guest OS does not change and proper planning is needed during the migration. vMotion migrations can be done from vSS to vDS and between vSS but it is not possible to migrate from vDS is vSS.
Long Distnace vMotion is an extension of cross vCenter vMotion. It uses Socket Buffer Resizing technique to ensure migrations succeed when the latency is high. Any underlying storage like VMFS and NFS is supported.
Content Library simplifies the template management easier when there are several vCenter Server instances spread across the world. It centrally stores templates, ISOs and scripts as catalogs and shares them using publish/subscribe model. Content Library also offers life cycle management by purging the old versions when a new content is updated.
Content Library is of three types; Local Catalog, Published Catalog, Subscribed Catalog. Local catalog os local to vCenter. Published cataog is a local catalog available for catalog subscribers. Subscribed catalog is a catalog that is in sync with the published catalog. Published catalog can be of two types based on the type of subscription; Automatic and On-Demand. In the On-Demand subscription, only the metadata is downloaded as a reference to the content published on the library.
vSphere Web Client
Web client has come a long way and is now fully functional and easy to use. It can now access multiple vCenter Servers from single web client page. All the features introduced from versio 5.1 are available only from Web Client and VMware recently has announced that C# client is not longer the supported client. VMRC has been integrated with Web Client now and hence it is possible to perform all the VM related actions as we did it on the C# client.
Hope this was informative. Thanks!