Hi,
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
virtualisation?
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?
Anything else?
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 [1]
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?
Thanks,
Nick
1.> 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
http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/6.1_Technical_Notes/qemu-kvm.html
