Thanks Richard! Very comprehensive answers. I will investigate in depth. Appreciate your response! -a <div class="gmail_quote">On Tue, Jun 7, 2011 at 11:06 AM, Richard W.M. Jones <<a href="mailto:rjones@redhat.com">rjones@redhat.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div class="im">On Mon, Jun 06, 2011 at 06:13:59PM -0400, al pat wrote: > I was looking at replacing vmware in our appliance with kvm and wanted to > get a feel for some > of the utilities vmware provides that I will need to have equivalent > function in kvm/qemu environment. > > I had a few question, and was looking at some help/pointers to investigate > further: > > 1. How to send log files to host log? I can use syslog for event reporting, > but is there a way, I can move a file from guest to host? </div>It's best (and most secure) to send logs to a remote server in real time. Standard syslog can do this. Just treat your virtual machines like networked real machines, and you won't go far wrong. <div class="im"> > 2. guest to host communication - logging messages (probably to appear in a > host log file), providing guest information like guest name, IP address etc </div>You can set up an ordinary TCP/IP network connection or a virtio-serial connection. There are about a dozen different options for guest to host communications: <a href="http://libvirt.org/formatdomain.html#elementsConsole" target="_blank">http://libvirt.org/formatdomain.html#elementsConsole</a> <div class="im"> > 3. Is there a way for the host to execute programs/scripts in guest? </div>Again, thinking of this from a network point of view, just use 'ssh'. It's widely available and secure. <div class="im"> > Looking for things like power down of guest </div>You can send an ACPI signal to the guest which (if the guest is listening) will power it off: <a href="http://virt-tools.org/learning/start-vm-with-virt-manager/" target="_blank">http://virt-tools.org/learning/start-vm-with-virt-manager/</a> <div class="im"> > 4. Is there a way to have heartbeat message between host and guest? </div>Depends what you want the heartbeat to do. A watchdog maybe? We support them in qemu and KVM: <a href="https://secure.wikimedia.org/wikipedia/en/wiki/Watchdog_timer" target="_blank">https://secure.wikimedia.org/wikipedia/en/wiki/Watchdog_timer</a> <a href="https://rwmj.wordpress.com/2010/03/03/what-is-a-watchdog/" target="_blank">https://rwmj.wordpress.com/2010/03/03/what-is-a-watchdog/</a> <div class="im"> > 5. Way for host to find the process and network information about the guest </div>virt-top It depends on exactly what information you want to find out. Using ordinary network methods is best if you have a lot of detailed information to collect from the guest, eg. using collectd. <a href="http://collectd.org/" target="_blank">http://collectd.org/</a> <div class="im"> > 6. how to find "hostid" of the guest in host? </div>Not sure what you mean by "hostid". The UUID and MAC address is available through libvirt, eg: virsh dumpxml Guest | grep '<uuid>' The hostname is accessible from virt-inspector. Rich. -- Richard Jones, Virtualization Group, Red Hat <a href="http://people.redhat.com/%7Erjones%0Avirt-top" target="_blank">http://people.redhat.com/~rjones virt-top</a> is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. <a href="http://et.redhat.com/%7Erjones/virt-top" target="_blank">http://et.redhat.com/~rjones/virt-top</a> </blockquote></div>