Composable Infrastructure Explained
Composable Infrastructure is essentially a form of “Infrastructure as Code.” It allows IT professionals to rapidly create the infrastructure required by individual workloads under software command (either GUI or API). Composable Infrastructure is employed by disaggregating the components of a physical server into separate pools of resources. For example, rather than using standard servers with internal drives as the fundamental component of a scale-out infrastructure, disk-lite servers (only enough disk to boot) can be used to create a compute pool and JBOD’s (Just a Bunch Of Disks) can create a storage pool.
Benefits of Composable Infrastructure Functionality
Attach any drive to any server, effectively composing servers and clusters optimized for the needs of a particular workload.
Add compute and storage resources to a workload with a few keyboard clicks to add more to the cluster.
Return resources to the pool for use by other applications once the workload is complete
Compose and re-compose under software control—a quick process with no physical reconfiguration.
Compute and storage resources are no longer trapped in separate silos.
How Composable Infrastructure Technology Works
Because servers and drives are physically separated in this architecture, they must be physically connected using an adapter, such as an SAS-to-Ethernet bridge. The adapter connects to the JBODs via the SAS ports and to the top-of-the-rack switch using Ethernet. With the servers connected to the top-of-the-rack switch, there is now a fabric which can connect any drive to any server.
If this fabric is sufficiently fast (10GigE for the TOR switch), then performance is identical to a bare metal server with Direct Attached Storage. No changes are required to the application stack because, to the software running on it, this structure is indistinguishable from a standard server. Server composition would happen within a rack (using the adapter and ToR switch), while clusters span multiple racks.
How to Get Started
Software composed clusters can be easily blended into data centers without changes to existing servers, storage, networks or applications. New disk-lite servers and JBODs can be added, and as refresh cycles occur, existing equipment can also be replaced with disaggregated components. Standard servers and composed servers can be combined in the same cluster.