8456ch_components.fm Draft Document for Review January 22, 2020 8:31 pm As a result, two additional rack management ethernet switches are required to be installed in  the base frame to provide the ethernet internal management network connections.  This switch pair feature needs to be ordered with the expansion frame. Figure 2-27 shows the  two additional network switches and the ethernet connections with an expansion frame and  three connected iPDU sets. 2.6.3 Power Domains Figure 2-27 DS8900F model 996 and E96 Ethernet connections To provide redundant power, the iPDUs are organized in groups so called power domains. As  shown on Figure 2-26 on page 57 and Figure 2-27 on page 58 the iPDUs on one side of the  racks form a power domain. If you look at the rear of the storage system the iPDUs on left  side of the racks is one (green) and the iPDUs on the right side of the rack are the other  (yellow) power domain.  Power redundancy is provided to each component such as CPCs, I/O enclosures,  management enclosure and HPFE Gen2 flash drive enclosures with redundant PSUs by  receiving its power for one of their PSUs from one power domain and the partner PSU from  the other. It is important that each power domain is supplied from an independent power source. Both  power domains should distribute to different AC main power sources (building power source  or service entrance) by connecting their iPDUs AC inline connectors to the related circuit.  58  IBM DS8900F Architecture and Implementation SMC 8126L2 SW3 T1 T2 T23 T24 SMC 8126L2 SW4 T1 T2 T23 T24 P1-T2 HMC2 P1-T1 HMC1 P1-C11-T1 P1-C1 1-T2 LPAR eth P1-C5-T1 P1-C5-T2 FOURMILE P1-C7-T1 P1-C7-T2 GAGNON C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 XC2 (ESS011) CEC Enclosure (Lower) P1-T2 HMC2 P1-T1 HMC1 P1-C11-T1 P1-C1 1-T2 LPAR eth P1-C5-T1 P1-C5-T2 FOURMILE P1-C7-T1 P1-C7-T2 GAGNON C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 XC1 (ESS01) CEC Enclosure (Upper) SW1-T6 SW1-T5 SW1-T2 SW1-T3 SW1-T4 SW1-T1 Private network: Black C1 RPC card C2 RPC card To MC2 keyboard To MC1 keyboard MC2-A MC1-A To MC2 monitor To MC1 monitor SW2-T5 SW2-T6 Private network: Gray SW2-T3 SW2-T4 SW2-T1 SW2-T2 MC2-B MC1-B IPDU R1E23 ETH J1 J2 J3 J4 J5 J6 J7 J8 J9 J10 J11 J12 IPDU R1E24 ETH J1 J2 J3 J4 J5 J6 J7 J8 J9 J10 J11 J12 IPDU R1E22 ETH J1 J2 J3 J4 J5 J6 J7 J8 J9 J10 J11 J12 IPDU R1E21 ETH J1 J2 J3 J4 J5 J6 J7 J8 J9 J10 J11 J12 IPDU R2E24 ETH J1 J2 J3 J4 J5 J6 J7 J8 J9 J10 J11 J12 IPDU R2E23 ETH J1 J2 J3 J4 J5 J6 J7 J8 J9 J10 J11 J12 The iPDU set of the expansion frame and the 2nd (upper) iPDU set of the base frame are  connected to the 2 additional managed ethernet switches The 2 additional managed ethernet  switches uplink to the ME switches: black network SW1-T1  gray network SW2-T2