Hi Anne and all.<br><br>Anne, thanks for your reply and suggestions.<br><br>I made some more investigation on this subject, found more information (maybe too many pages, wikies, blogs, emails, etc...) and these are my findings and comments:<br>
<br>0) This is the page where I found most of the states (<a href="http://docs.openstack.org/developer/nova/devref/vmstates.html">http://docs.openstack.org/developer/nova/devref/vmstates.html</a>). Unfortunately the page does not tell the whole story in terms of what a status means and when a command is applicable according to the Hypervisor you are using (see more below).<br>
At least one state page (e.g. STOPPED) seems to be wrong,<br>Also this page reports useful information on command, in general <a href="https://gist.github.com/2714727" target="_blank">https://gist.github.com/2714727</a>.<br>
<br>1) The difference between SUSPENDED and PAUSED should be related to where the VM 'contents' are stored (see <a href="http://docs.openstack.org/trunk/openstack-compute/admin/content/pausing-and-suspending-instances.html" target="_blank">http://docs.openstack.org/trunk/openstack-compute/admin/content/pausing-and-suspending-instances.html</a>). In both cases the execution of the VM is 'frozen' (computation is temporary stopped) but if the VM is suspended its contents are stored onto the node disk; if paused, the contents are stored into node's RAM. (<a href="http://docs.openstack.org/trunk/openstack-compute/admin/content/nova_cli_suspend_resume.html" target="_blank">http://docs.openstack.org/trunk/openstack-compute/admin/content/nova_cli_suspend_resume.html</a>)<br>
<br>2) The RESCUE state is described here (<a href="http://docs.openstack.org/developer/nova/api_ext/ext_rescue.html" target="_blank">http://docs.openstack.org/developer/nova/api_ext/ext_rescue.html</a>) and seems to be available for XenServer, only (<a href="http://virtualandy.wordpress.com/2012/11/04/deep-dive-openstack-nova-rescue-mode-with-xenapi-xenserver/" target="_blank">http://virtualandy.wordpress.com/2012/11/04/deep-dive-openstack-nova-rescue-mode-with-xenapi-xenserver/</a>). Very likely, there are some settings to do for making this feature work (seek word "rescue" here <a href="http://wiki.openstack.org/NovaConfigOptions" target="_blank">http://wiki.openstack.org/NovaConfigOptions</a>). <br>
<br>3) States RESIZE, REVERT-RESIZE, VERIFY_RESIZE with related commands "nova resize", "nova revert-resize" and "nova resize-revert" should allow changes to the flavor of a currently running VM> I was not able to verify how these things work probably because I'm testing with KVM and these features should be for XenServer, only (<a href="http://virtualandy.wordpress.com/2012/09/13/deep-dive-nova-resize-up-xenapi/" target="_blank">http://virtualandy.wordpress.com/2012/09/13/deep-dive-nova-resize-up-xenapi/</a>)<br>
Also resizing needs some nova configuration (seek for the word "resize" here <a href="http://wiki.openstack.org/NovaConfigOptions" target="_blank">http://wiki.openstack.org/NovaConfigOptions</a>). I found a usage example here <a href="https://gist.github.com/2714727" target="_blank">https://gist.github.com/2714727</a> but I was not able to reproduce.<br>
My instance does not transition from ACTIVE to RESIZE when I submit "nova resize". I also tried from SUSPENDED and PAUSE, without positive results. My hunch is that the problem is in the hypervisor I'm using. <br>
<br><br>4) DELETED state should be "transient" in the sense that it is entered when you "nova delete" an instance. It is automatically left when the "termination procedure" finishes. <br><br>
5) SHUTOFF state can be reached by submitting "nova stop" as far as I understand, what's reported here is <a href="http://docs.openstack.org/api/openstack-compute/2/content/List_Servers-d1e2078.html" target="_blank">http://docs.openstack.org/api/openstack-compute/2/content/List_Servers-d1e2078.html</a>. either out-of-date or plain wrong.<br>
<br>6) I wasn't able to reach UNKNOWN state. The way for getting to it is, well, unknown<br><br>7) REBOOT and HARD_REBOOT are entered respectively when you submit "nova reboot" and "nova reboot --hard". Both are temporary meaning that they are left as soon as the rebooting procedure terminates.<br>
<br>8) I didn't find any page mentioning MIGRATING state that is entered when you migrate an instance (I just tried "nova live-migration")<br><br>Can anybody confirm?<br><br>Thanks,<br>Marco.<br><br><br><br>
<div class="gmail_quote">On Tue, Nov 20, 2012 at 10:20 PM, Anne Gentle <span dir="ltr"><<a href="mailto:anne@openstack.org" target="_blank">anne@openstack.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Hi Marco -<br>
Great questions, and I won't tell you to read the fine manual because<br>
I know you do and log the most excellent bugs. :) But more commentary<br>
below for how to do some detective work. I would still like for<br>
someone to answer these questions in detail.<br>
<div><div><br>
On Tue, Nov 20, 2012 at 4:46 AM, Marco CONSONNI <<a href="mailto:mcocmo62@gmail.com" target="_blank">mcocmo62@gmail.com</a>> wrote:<br>
> Hello,<br>
><br>
><br>
><br>
> I’m playing with nova CLI and I found that there are several commands for<br>
> managing the current state of instances running in the cloud.<br>
><br>
><br>
><br>
> These are the states I found:<br>
><br>
><br>
><br>
> · initial<br>
> · build<br>
> · active<br>
> · shutoff<br>
> · suspended<br>
> · rescue<br>
> · paused<br>
> · reboot<br>
><br>
><br>
><br>
> And these are the nova commands for changing the current state:<br>
><br>
><br>
><br>
> · boot<br>
> · pause<br>
> · reboot<br>
> · rescue<br>
> · resume<br>
> · start<br>
> · stop<br>
> · suspend<br>
> · unpause<br>
> · unrescue<br>
><br>
><br>
><br>
> QUESTION: Is there any explanation on the meaning of the states? In<br>
> particular, what’s the difference between SUSPENDED, PAUSED and RESCUE?<br>
<br>
</div></div>The document for this info is the Compute API spec, specifically<br>
<a href="http://docs.openstack.org/api/openstack-compute/2/content/List_Servers-d1e2078.html" target="_blank">http://docs.openstack.org/api/openstack-compute/2/content/List_Servers-d1e2078.html</a>.<br>
However since it is a spec it is likely that there are undocumented<br>
things going on here.<br>
<br>
Also the API definitions don't tell the whole story because the nova<br>
CLI parameter "pause" is doing something with the API that you can<br>
find out using the nova --debug command.<br>
<br>
nova --debug pause <servername><br>
<br>
It seems like it's doing something with extensions, such as<br>
"OS-EXT-STS:vm_state" "OS-EXT-STS:power_state" so dig further there.<br>
You can search for Extended Server status on<br>
<a href="http://api.openstack.org/api-ref.html" target="_blank">http://api.openstack.org/api-ref.html</a>.<br>
<br>
Boy, trying to find this info myself shows what a nightmare this info<br>
is to dig into, and I apologize for that. Sure shows a need for more<br>
API documentation for real usage.<br>
<br>
Thanks,<br>
Anne<br>
<div><br>
><br>
><br>
> Another command changes the status and, from what I found, it always changes<br>
> that to ERROR.<br>
><br>
> The command is “nova reset-state”.<br>
><br>
><br>
><br>
> QUESTION: what’s the semantics of this command?<br>
><br>
><br>
><br>
><br>
><br>
> Then, I found some other commands that sound like status management command<br>
> but, actually they are not:<br>
><br>
><br>
><br>
> · Lock<br>
> · Unlock<br>
><br>
><br>
><br>
> QUESTION: What’s the meaning of these?<br>
><br>
><br>
><br>
><br>
><br>
> Marco.<br>
><br>
><br>
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><br>
</blockquote></div><br>