DL380 G6 Power Supply Redundancy

[MikkaR]

I have a ProLiant DL380 G6 with redundant Power Supplies that we are setting up. Both are plugged in to a power source.

Does the hardware Cycle back and forth between the Primary and Secondary power supplies... and/or will it take one off line at any point for testing or load reapportioning, etc...

The reason I ask is our new server has been plugged in for 9-days. It has not been fully setup and meshed into the rack. So for the short term it is plugged into a retail desktop UPS.

The server went down hard at 2:26. We checked the OS event logs. We checked the "HP Integrated Management Logs". We checked the physical connections. We check the UPS uptime.... nothing.

Other devices and UPSs are plugged into the same power source. None went down, and no alarms went off. The UPS in question indicates that it has been online for many days with no breaks.

The UPS in question has an iterface that states it had NO power issues for over an hour BEFORE the server went down, and none during.

We looked closer at the UPS (it is only a temporary from BestBuy) and it has a "Master" "Slave" plug arrangement. If the "Master" load is turned off it triggers the UPS to kill power to all "Slave" power outlets. Both Power Supplies were plugged into the same UPS with one as the "Master" and one as the "Slave"... yeah I know, pretty stupid in hindsight.

But that gets me back to the original question posed above: Do the Power Supplies change load back-and-forth in Redundancy mode... because nothing else explains why the server went down.

[Big_Dave]

Usually one power supply is the primary and the other is the secondary. The load should be proportioned across both power supplies. You should be able to yank the cord of one the the power supplies without the system going down.  Plug it back in and do the same for the other power supply. If your server is drawing less than 10 amps a side then your electrical source needs to be breakered for 20 amps.

The best situation for redundancy is to have redundant power supplies connected to separate independent power sources (A and B) with each source isolated from the other and backed up with batteries and generator.  This is how a commerical data center would do it.  Even then, the most critical data centers use three (3) separate power feeds, each sized to run the full load at 70% of capacity.  Having dual power sources for a data center provides the ability for maintenance activities to occur without losing service, assuming that most critical equipment have dual power feeds.

The slave side of a typical APC power supply is usually used by the monitor.  When the master outlet is detected in a low power or no power state then the slave outlet is switched off.