[SOLVED] Upgrade from 6.0 to 6.3 CPU usage increase by 100% :-)

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Renowned Member
Mar 14, 2012
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Hi guys,

recently I upgraded two node cluster to four nodes from 6.0 to 6.3.
I migrated VMs (some online, som offline) to the new nodes.

On the new nodes we have the same series (E5 v2) CPUs, just around 1/5 faster per core and more cores.
The thing I notice is, that CPU usage (with the same machines and same workload) went up from 20% to >50% per host.

I have no explanation for this, if anything it should drop.

I will now play with intel-microcode and disabling CPU flaws protections to see, if it will help reduce CPU usage.
Other than this, I have no idea what could case the increase in CPU usage.
Any hints are welcome.
 
I fixed it by installing latest intel microcode and now every operation is much faster.
Even ZFS CPU usage decreased dramatically.