BL p-Class power shelf requirements - 1 or 2 power shelves needed?

[ThomasO]

Hi All

My current setup is as follows:
- 3 server shelves with 18 BL20p servers in total
- Each shelf has 2x GbE2 interconnect switches with FC passthrough.
- 2 3phase power shelves
- Scalable bus bar to connect everything together from a power perspective

My question:
Can I unplug one of these power shelves and still be able to power everything mentioned above? I guess I will at least loose redundancy, but is it a possible setup?

The problem is that I am looking at getting a c-Class shelf in, but I don't have any more available power circuits, so I am looking at utilizing one of the 3phase circuits currently in use by my p-Class infrastructure.

Some advice is greatly appreciated.

Thanks.

/Thomas

[bryanVF · Accepted solution]

Basically each enclosure (fully populated) needs 2 power supplies.

connect to the serial port, and using a telnet session to the power enclosure. then go to the power section you will be able to see how many power are you servers using.
If it reports less than 50% you can disconnect one of the power enclosures with no problem.

This will depends on each server configuration.
If you have fully configure each server you probably will not have enough power (full memory full CPU full mezzanines, ETC).

I hope this information will be help full.

Another thing you can use to verify if you have more than enough power you can try using the p class power sizer you will have to put your servers configuration and it will tell you how much power you need.

http://g3w1656g-vip.houston.hp.com/sb/ProLiantBladePowerSizer/ASPNET/Download.aspx?SAId=BPS&SAVer=3.2&strHomePath=../SB/ProLiantBladePowerSizer/ASPNET/index.aspx&UserId=PLMSizerUser&Tree=True&bVisio=False
this will tell you if need 2 or just one power enclosure

[ThomasO]

Hi

Thanks a lot for the feedback.
Which serial port are you refering to?
I checked the back of each power enclosure and there is a port with a black cap saying "service port". Is this the one I should connect to?

Regards,
Thomas

[ThomasO]

I tried to connect to the ports I mentioned above and I guess if was the right ones.

Attached is a PDF with a few screenshots.

I am not sure if I fully understand the power readings, so it would be great if someone could comment.

Thanks.

/Thomas

[bryanVF]

I saw the screen shots.
By looking at the configuration you have the bottom power enclosure is the primary.
Is using 5169 of 17442.

So one power enclosure is good enough for your servers.

The secondary power enclosure is on working fine but is not supplying any power to the blades.


so you can take out the second power enclosure obviously this is not a hot procedure.

As summary the answer for your question is yes, you can use just one power enclosure.

[ThomasO]

Thanks again for the feedback.

From what you mention, my bottom power enclosure is the primary power source. The top power enclosure is stated as "Secondary Power Source".
I also noticed on the secondary one that is says "Enclosure Power Used: 1377W".

You mentioned that the secondary enclosure is not supplying any power to the blades. How do you see that?

Thanks.

/Thomas