[Libguestfs] Can I use guestfish to benchmark qemu performance?

[Richard W.M. Jones]

On Thu, Apr 02, 2020 at 11:27:57PM +0200, chl501 at tutanota.com wrote:
> I come across this page libguestfs.org/guestfs-performance.1.html <http://libguestfs.org/guestfs-performance.1.html> This raises my interest. I am currently learning how to benchmark performance qemu. So here is my questions:
> 
> 1. Can I use guestfish or any tools provided by libguestfs to benchmark qemu? How? (The command I use below is correct or what's the correct command to execute it?) 

Yes, see:

https://github.com/libguestfs/libguestfs-analysis-tools

and my various postings on performance in 2016:

https://rwmj.wordpress.com/2016/03/
https://rwmj.wordpress.com/2016/05/

> The preliminarily run I use is "time guestfish --ro -a disk.img -i exit run -v -x" and its output on console wrt the time are
> 
> real	0m3.713s
> user	0m1.968s
> sys	0m0.741s

This is reasonable, considering that debugging is enabled.

> There many output with -v -x params enabled
> 
> ...
> guestfsd: => internal_autosync (0x11a) took 0.05 secs
> libguestfs: trace: internal_autosync = 0
> libguestfs: sending SIGTERM to process 11629
> libguestfs: qemu maxrss 235720K
> libguestfs: trace: shutdown = 0
> libguestfs: trace: close
> libguestfs: closing guestfs handle 0x562ae3df6c10 (state 0)
> libguestfs: command: run: rm
> libguestfs: command: run: \ -rf /tmp/libguestfsIDYj9s
> libguestfs: command: run: rm
> libguestfs: command: run: \ -rf /run/user/1000/libguestfs2SKM4c
> 
> 2. If the tool such as guestfish (or any other tools provided by libguestfs) can be used to benchmark qemu's performance, is it possible to identify the execution time spent on different processes e.g. init? How?
> 
> 3. How do I interpret the output with -v -x for the command guestfish (like the command being executed below)?

The analysis tools basically do all this.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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