What are the tools available to place on the level on top of VMWare or Xen (or other VM managers) that would monitor the VMs?
I know there are a few solutions like Netuitive, CA Infrastructure Manager / eHealth, Nimsoft - what are the areas of application and how popular are they?
CA has root-cause analysis of potential problems with the host. Is there something that performs other types of analysis or even attempts to fix the problems?
Alex, which VM's are you talking about in particular ? Xen, vmware, VirtualPC, etc? If you just want to monitor performance & status - you can treat them like regular servers - nagios or something. But I haven't heard of a tool that would monitor their "performance as VM's" for various architectures.
You can also setup nagios or groundwork or spunk or something to monitor your hosts if you have heterogeneous environment with both vmware and xen.
Could you clarify or expand a little bit?
Based on your comment below:
Ok I see, then the tools I mentioned may work for you. I use GroundWork - it's based on nagios - but in addition has some nicer and more developed graphs and history analysis, than nagios and works with ldap :-) (see monitoringforge.org - both commercial and free - for over 2000 extensions, including some support for xen and vmware).
Also check out splunk ( they have a commmunity version) and there is another interesting tool called Spiceworks. I tried both, but like groundwork more for my needs.
To be honest I think splunk is more of what you are looking for since it's more of a data collector and then you can do what you want with that data - like run reports in mysql or write some nifty web app that draws graphs and such.
P.S.: A word of warning - I run groundwork community version on Debian and still it required a 2.8 ghz dual-core cpu and 4 gigs of ram to run properly, it's kind of a memory hog, but other than that it's been running without a hitch for a year.