Administrator Guide

Executive summary
4 In-band or out-of-band: Advantages of iDRAC and iSM compared to OMSA | ID 423
Executive summary
The traditional approach to server systems management has been to install an agent in the server operating
system and proceed from there. These “in-band” agents were required to connect to various platform components
to be able to discover, configure, update, and monitor the device. In band agents were the de facto method for
server management.
However, Dell EMC changed this paradigm in 2012 with the introduction of the first agent free architecture. No
agents in the operating system or hypervisor to inventory as all management is done in band. In band, also called
side band, is the iDRAC communicating directly to the components on the system board. The iDRAC9 is further
reducing the need for in band agents as a result of many new “bare-metal” or out-of-band management
capabilities.
As Dell EMC has added more improvements to iDRAC9 and the latest PowerEdge servers, the gap between in-
band and out-of-band management capabilities has become narrow. There are still some functions that require
the use of the in-band agent—either the lightweight iDRAC Service Module (iSM) or OpenManage Server
Administrator (OMSA.) This paper discusses the unique iDRAC9 architecture and integration with vendors for
peripherals such as network cards. A detailed functionality chart helps identify supported management functions
to help IT admins transition from in band to out of band solutions.