How do I control UL via jcmd VM.log?

[Staffan Larsen]

The documentation clearly needs som work. But “jcmd <pid> help VM.log” gives you some hints.

I think this does what you want (although I’m not completely sure):

$ jcmd <pid> VM.log what=all=trace


> On 27 jan. 2016, at 14:48, Thomas Stüfe <thomas.stuefe at gmail.com> wrote:
> 
> Hi all,
> 
> sorry if this is a stupid question. I have trouble figuring out the syntax
> to enable Logging dynamically using jcmd for a life process.
> 
> Whatever argument I hand down to the VM.log command, I
> get java.lang.IllegalArgumentException.
> 
> Examples:
> 
> ./images/jdk/bin/jcmd 12680 VM.log  all
> ./images/jdk/bin/jcmd 12680 VM.log  all=trace
> ./images/jdk/bin/jcmd 12680 'VM.log  all=trace'
> ...
> nothing works.
> 
> 
> I also looked through https://bugs.openjdk.java.net/browse/JDK-8046148 but
> did not find a clear answer beside "Everything that can be specified on the
> command line can also be specified dynamically with Diagnostic Commands."
> which did not help much.
> 
> What am I doing wrong?
> 
> Thanks and Kind Regards, Thomas