On 06.03.2017 14:14, Matczak, KrzysztofX wrote: > Hello > > I'm trying to find out how to detect if domain was destroyed and brought up between two time moments, let's call it reads. > So far the best approach I could find is to compare domain ID from previous and current read. > And this is my first question : is that reliable solution ? Or do you know any better ? Listen to the events. If domain is destroyed/started libvirt fires up an event. The domain ID is not necessarily unique. For instance: a) start a domain and assume it's the first one started. It will have ID=1. b) destroy it. c) restart libvirtd. d) start the domain again - it will have ID=1. This applies to qemu driver, other drivers might have different meaning for domain IDs - e.g. LXC driver reports PID of the container's init in which case you can make no assumptions about it. > > And related question is how to resolve virDomainPtr into domain ID ? virDomainGetID(). > The only verified way of getting domain ID I know is to memorize it's UUID, then call virConnectListDomains , then iterate over all returned domain IDs and resolve each one's pointer using virDomainLookupByID , then get UUID by virDomainGetUUIDString get domain ID of matching UUID's . > It seems too complex and I expect noticeable performance overhead, so looking for something lighter. > > I'm trying to get current domain ID using API function : > > char * virDomainGetMetadata (virDomainPtr domain, int type, const char * uri, unsigned int flags) > > I'm not sure it's relevant function, since domain ID is contained not in metadata subsection but in opening <domain> markup. > In fact I wasn't even able to get any data using that function call since I don't know how to construct valid URI. Do you know any doc or examples explaining that ? Documentation might come handy: http://libvirt.org/html/libvirt-libvirt-domain.html#virDomainSetMetadata http://libvirt.org/html/libvirt-libvirt-domain.html#virDomainGetMetadata or just look into our test suite: http://libvirt.org/git/?p=libvirt.git;a=blob;f=tests/metadatatest.c;h=55dc841254bcfda0742d22580723bf4acac172b4;hb=HEAD Michal _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
