[Linux-PowerEdge] Dell R210-II - Unable to disable hyperthreading?
matt at theratshack.net
Thu Sep 24 13:45:10 CDT 2015
Hello Linux Poweredge group:
For the past month, I have been tasked with a special problem across a
worldwide fleet of Dell R210-II servers. These servers are all running
Centos 6.7 and until recently have been working well. We started
noticing an issue with processor load but were able to successfully
trace it back to the fact that some servers have hyperthreading enabled
and some did not. Further reviews indicated that the HT enabled servers
were encountering the load issues and that the HT disabled servers were
not. The decision was made by management to disable HT on all servers
fleet-wide in order to mitigate the load issue and I have been tasked
with doing just that.
I've set out changing HT enablement with some success (10 out of 14
servers were able to have HT disabled using omconfig) however these last
four have me scratching my head. I can't figure out why these four
servers won't allow me to change HT to disabled. While most of the test
group was on BIOS 1.4.0, one of the failed servers was also on v1.4.0
and the other three were on v1.1.4.
All four servers show the same symptoms:
1) The command "./omconfig chassis biossetup attribute=LogicalProc
setting=Disabled passwd=********************" results in the error
"Error! The operation was unsuccessful because the attribute cannot be
configured using Server Administrator." (This appears to be "working"
syntax for v1.4.0 BIOS servers)
2) The command "./omconfig chassis biossetup attribute=cpuht
setting=disabled" results in the error "Error! The specified attribute
name is not valid. See command help for valid attribute name(s)." (This
appears to be "working" syntax for v1.1.1 BIOS, although these are rare
in the fleet. Only one server with this BIOS version was seen in the
test group and the command worked successfully.)
3) The command "./omconfig chassis biossetup -?" shows no properties
whereas all the "working" servers showed all of the available properties
able to be configured with omconfig.
4) The output of the omconfig commands does not change if OSMA v8.2.0 or
v8.1.0 is used (although I've upgraded OSMA on the four non-working
servers to 8.2.0 just to be sure).
5) Comparing dmidecode output on the four affected servers with the
"good" servers reveals no significant changes relating to BIOS or
hardware except where expected (RAM manufacturers, processors, hard
According to dsu --inventory, the only difference is the BIOS versions.
I haven't had a BIOS v1.1.4 success yet, and BIOS v1.4.0 is successful
except for one failure so I can't figure out the commonality between the
failures. I can't just simply say "BIOS v1.1.4 is bad and v1.4.0 is good".
1. OpenManage Server Administrator ( Version : 8.2.0 )
2. BIOS ( Version : 1.1.4 ) ** OR ** BIOS ( Version : 1.4.0 )
3. iDRAC ( Version : 1.57.57.00 )
4. NetXtreme BCM5720 Gigabit Ethernet PCIe (eth0) ( Version : 7.10.17 )
5. NetXtreme BCM5720 Gigabit Ethernet PCIe (eth1) ( Version : 7.10.17 )
If anyone can shed some light on why I can't get these four servers to
switch HT, I would be very grateful. If there is additional information
I can provide to assist with data collection, please let me know.
Thank you in advance!
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