2. The resemblance is uncanny
When you took your first class for VMware vSphere, you would have noticed that VMware platform is based on three-tier architecture. It is quite easy to learn NetBackup if you are already a certified VMware professional.
You have virtual machines; this is the life blood of the organization. This is where your applications are running. Multiple virtual machines are hosted by ESXi hosts. Multiple ESXi hosts are managed a vCenter server. That is how the scalability is achieved and vSphere became an enterprise platform.
NetBackup pioneered this model more than a decade ago. It features three tiers. At the lowest level is NetBackup clients. Multiple clients may be protected using a NetBackup media server. Multiple media servers are managed by a NetBackup master server.
NetBackup clients can be a physical systems (a Windows PC, a Mac, a UNIX system hosting an Oracle database etc.) sending backup streams to a media server. In a virtual environment, it can be a virtual machine or a physical system that can read data from VMware datastore. It is important to remember that your production virtual machines themselves do not stream backups, that operation is offloaded to a dedicated VM or a physical system. This system is known as VMware backup host. Thus NetBackup is providing agent-less backups for your virtual machines.
Now let us look at the media server. In terms of our architectural comparison, we compared a media server in NetBackup domain to an ESXi host in vSphere domain. Just like ESXi hosts have storage connected for serving virtual machines, media server has storage attached to it for serving backup clients. The storage connected used by ESX hosts is referred to as data store or primary storage. It is on primary storage that your production virtual machines and applications live. The storage attached to media servers are known as secondary storage or backup storage. It is used for the purpose of storing the backups.
You know that ESXi systems can support multiple kinds of data stores. You have NFS data stores and VMFS data stores. You also know that VMFS can be on direct attached, Fibre Channel SAN attached or iSCSI SAN attached. Similarly media server can have secondary storage attached to it. There could be plain disk storage, capacity managed disk storage, deduplicated disk storage or even a tape library. The disk storage may be directly mounted on media server or being served from dedicated storage server.
We know that multiple ESXi hosts can share the same data store. Similarly it is multiple media servers can share a storage server or tape library. Just like how VMware DRS can start VMs based on where least ESXi hosts, backup jobs are load balanced across media servers.
We know that vCenter is really the center of vSphere. vCenter is the management control station. Similarly, NetBackup master server is the center of NetBackup. Just like vCenter, master server hosts a central database and manages data protection for the entire backup environment.
In a vSphere domain ESXi (the ESXi hypervisor) and VMs coexist in a physical system. In NetBackup domain the media server and clients are almost always on different physical systems. There are some exceptions to this rule.
vCenter is generally a separate system for enterprise environments. For smaller environments, it could also be a VM on and ESXi host. Similarly, NetBackup master server is a separate system for large environments. It may also coexist with a media server.
It is worth mentioning that NetBackup also has a fourth tier. It is called NetBackup OpsCenter. NetBackup OpsCenter can do management and reporting on a number of NetBackup domains that are served by different master servers. This layer makes NetBackup even better scalability. You may have data centers across the globe. A NetBackup master server at each data center managers its own media servers that are protecting the clients. All these master servers report into OpsCenter. This is it like a super control and command center. By logging into this central OpsCenter dashboard, you can get a single-pane-of-glass view for the entire data protection infrastructure.
For a very crude comparison, think about vCenter Server Heartbeat that lets you manage multiple vCenter instances. OpsCenter is like vCenter heartbeat but much superior. OpsCenter is a standalone system with its own database for manages, monitor and report tasks. vCenter Heartbeat is more or less a glue that makes it possible to view all instances of vCenter from a single vSphere client GUI.
That is it for today! We will move on to details on each of these three layers in subsequent blogs.