Instaling 2CPUs in 4 blades ramps 6 fans to 10000rpm

Ever since I installed additional CPUs into each of four blades (installed in positions 1,2,3 and 4) an aforementioned issue with M1000e blade enclosure turned up. Like stated above, RPM for cooling modules (fans) 2,3,5,6,8, and 9 ramped to over 10000rpm each, while the remaining 3 cooling modules kept the usual performance of around 5000rpm. This makes the blade enclosure disturbingly loud.
I've searched on-line for this behavior, and found only this issue of fans 7,8 and 9 spinning at 12000rpm+ due to a firmware bug:
http://www.delltechcenter.com/thread/1699881/Questions+from+my+customer...
that can be resolved by updating the firmware. Now, the CMC firmware is updated to the latest version available (2.30 A00).

Before I take any steps further, and update any remaining old firmware, I'd like to know if this is expected behavior of blade enclosure when one installs additional CPUs per blade, and if any of you here have more than one CPU per blade. There are 8 more blades installed in positions 9-16 each with a single CPU. The position of dual CPU blades and the "problematic" cooling modules makes me believe these are related. BIOS for these four blades is update to the latest version.

Thanks in advance,
Milos.

Responses(2)

ibigpapa

1 Message

0

June 9th, 2010 15:00

Blades have separate cooling zones. The cooling is dependant on the hardware installed. Installing more processors increases the heat that needs to be removed by the fans. I would have to look into the cooling zones to figure out what fans are used to cool the modules. This information should be available in the owners guide on support.dell.com

milosb

2 Posts

0

June 18th, 2010 02:00

Hello again,

I'm happy to report that the problem has been resolved. The culprit was the incompatibility between the firmware versions of CMC and iDRAC that resulted in this behavior. CMC v2.30 requires iDRAC version of 1.52, CPLD 1.1.1 and BIOS 2.3.1 (these versions are for M600 blades in particular). As soon as I finished the update of the last iDRAC, the fans from the cooling zone of these 4 blades with 2 CPUs each and additional RAM, dropped rpm from 11.5k to 7.5k. Remaining fans stayed at 5.5k rpm.

When we distributed these 4 blades 'all across the enclosure', ALL of the cooling fans ramped to 7.5k rpm, but the noise was still acceptable (i.e. not as nearly as loud as earlier). If we placed them in slots 1,2,9 and 10 probably only fans 3,6,9 would go up to 7.5k rpm

Thanks for your comments and I hope this helps someone in the future.

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