We've been validating as much of our configuration as is possible given our general OVM stability issues, and received a recommendation from Oracle to disable HyperThreading and C states for our x4470-m2 servers. We also found documentation that said we should disable VT-d, which we also disabled.
I'm wondering if anybody has any real world experience on these fronts. I'd rather have HyperThreading available if it won't undermine stability. They tech said generally you can't have Virtualization Extensions and HyperThreading on at the same time, but we're able to with our systems.
What kind of setups are you all using? We're on VM 3.1.1.
I run 4 way 4470 m2 servers. Some with 8 core processors and some with 10 core processors. I also run some 4170 servers but I use the 4470M2 for all my database RAC nodes.
What software version you running on the ILOM? I run v188.8.131.52.c r72950
I tried running the latest before I went live and I had a lot of issues with the ILOM wanting to lock up on me. I reverted to the ILOM version above and haven't had any issue since. I use Oracle 7420 ZFS storage with FC for database LUNS/Diskgroups and NFS for repos over bonded 10GB ethernet links on Cisco Nexus switches.
The newest ILOM looks to be 1.3.1. I tried it and the web interface started immediately locking up on me when navigating. Even to the point I had to ssh into the ILOM and reboot it. I've been waiting on the second release of 1.3.1.etc before trying again.
I don't remember if I disabled it or not. I don't know a way of telling without actually going in the BIOS itself. Do you know of way and I'll check what I have.
I'm running 3.1.1-485 on everything and haven't had much of an issue. I have seen a couple instances in which temp files in the /var/tmp path would grow without much of an explanation of why but I've seen similar situation with non virtual Linux installations. Are you running powerpath? In the past, I've had serious issues trying to get multipathing to work properly with EMC equipment without powerpath. Not with Oracle VM just native multipathing in Linux. I almost purchased a EMC VNX5700 but couldn't bring myself to do it with all the unknowns with Oracle VM and powerpath at the time. EMC has since released Powerpath for Oracle VM 3.1.1.
The easiest way to tell if HyperThreading is on or off that I'm aware of is to see how many processors OVM Manager reports. I have two 8-core Xeons. If I have HyperThreading on, OVM thinks I have 32 cores available. If I have HyperThreading off, OVM thinks I have 16 cores available.
Would you be interested in comparing notes via email?