This read-only Gauge32 field is the 'kernelMemTotal' property of the 'FexSystemStats' managed object in Cisco UCS Manager's equipment-inventory schema reporting the total kernel memory available on the FEX's onboard control-plane OS. This is essentially a fixed hardware/software constant for a given FEX model, so it mainly serves as the denominator against which KernelMemFree is judged, rather than something expected to fluctuate on its own. A FEX reporting a stable KernelMemTotal of 256MB across every sample lets an admin quickly compute that a KernelMemFree of 40MB corresponds to only about 16% headroom.