HP DL360 Critical factors in intra-rack power distribution planning for high-d - Page 7

Segmented power distribution In high-density systems where a single rack can support hundreds of users at a time, the power infrastructure should be designed so that a single system failure will have minimal effect on overall operations. Segmenting servers into groups for power distribution reduces the chance for unscheduled downtime resulting from overload or maintenance conditions that might otherwise shut down everything else in the rack. Segmenting servers into two or more groups also facilitates proper cable management and serviceability. Segmenting can reduce the amount of inrush current associated with servers by allowing IT administrators to sequentially power up server groups. Circuits can be segmented by using a modular system of control cores and extension strips (Figure 5A) or by using monitored PDUs that individually support multiple load segments (Figure 5B). In either case, a circuit breaker is associated with each load segment (LS). Figure 5. Segmented power distribution A. Segmenting with HP Modular PDU components LS1 Ext. Strip PS A PS B HP ProLiant servers 1 thru 8 LS2 Ext. Strip PS A PS B HP ProLiant servers 9 thru 16 To other extension strips B. Segmenting with an HP Monitored PDU component PDU LS1 PS A PS B HP ProLiant servers 1 thru 8 LS2 PS A PS B HP ProLiant servers 9 thru 16 LS3 PS A PS B HP ProLiant servers 17 thru 24 Control Core VAC input VAC input 7