[CentOS-virt] profiling KVM i/o on CentOS 5
oinksocket at letterboxes.org
Thu Aug 18 12:52:50 EDT 2011
I am wondering what tools are available to troubleshoot KVM I/O problems on
CentOS 5, given that the kernel is 2.6.18 with some backports to support
kvm_stat / kvmtrace - These seem to be available in the kvm-tools package.
ftrace related things seem not to be available.
OProfile is available, can it be used?
Also, SystemTap is available, can it be used?
I don't currently have any experience using any of those, except for a brief
experiment with OProfile, but my impression is that it's more of an
event-counting tool - I'm not sure it can time function call execution times.
Which makes me think SystemTap is better suited. However, this reference 
makes me wonder if it can only be used with QEMU/KVM CentOS 6.
Has anyone any experience or prior art they can share or reference, specifically
with profiling virtio_blk?
> BZ#632722 - This update introduces support for tracing of events within QEMU;
> the tracing is similar in its style to DTrace. When used in conjunction with
> SystemTap, it is now possible to trace internal QEMU events such as I/O
> operations and memory allocations
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