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Should we use irqbalance in a VMware guest? I'm very sure this benefits bare-metal installations on multi-processor systems. I'm rather unsure if this benefits VMware guests, even VMware multi-processor guests, and I'm interested in how it would benefit a VMware guest. This also applies to Xen, Amazon AWS, and other hypervisor guest platforms. Thanks!!

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Although I've not got a machine to look at myself, I'd be very surprised if it did not make a difference - what does 'cat /proc/interrupts' tell you? – symcbean Jun 7 '12 at 9:00
up vote 5 down vote accepted

I had looked at this before but I never found much as far as using it with VMware but it seems XenServer has some good documentation found here for at least one benefit.

It speaks mostly of improving network throughput by using irqbalance. Citrix also has a whitepaper on this:

Though I cannot test this right now, I believe you would want to keep it disabled for any VMs that are 1-CPU hosts. It may also depend on which operating systems you are installing. I have seen before that Fedora wishes for irqbalance to be turned off.

symcbean is correct about looking at /proc/interrupts. One thing you can do is to check if a task is running on the same core then isntall irqbalance and check it again to see the difference. Anyway I hope that helps a little

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