Software Composable Infrastructure

Software Composable Infrastructure Explained

Software 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). SCI 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 SCI Functionality

  • Attach any drive to any server, effectively composing servers and clusters optimized for the needs of a particular workload.

  • Add computer or storage resources to a workload with a few keyboard click to add more to the cluster.

  • Return resources to the pool for use by other applications once the workload is complete

  • Composition and re-composition happens under software control—a quick process requiring no physical touch or reconfiguration of any equipment.

  • Resources are no longer trapped in separate silos.

Because servers and drives are physically separated in SCI 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), 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.

Implementing Software Composable Infrastructure

  • No replacement of existing servers required.

  • Simply deploy new racks using SCI architecture, which will work perfectly with the existing standard servers.

  • Combine standard servers and composed servers in the same cluster.

  • When upgrading existing equipment, replace them with disaggregated components.