Re: [libvirt] [PATCH 2/2] getstats: add block.n.source stat

On 11/25/14 06:21, Eric Blake wrote: > I noticed that for an offline domain, 'virsh domstats --block $dom' > was producing just the domain name, with no stats. But the older > 'virsh domblkinfo' works just fine on offline domains. Furthermore, > I'm about to make block stats optionally more complex to cover > backing chains, where block.count will no longer equal the number > of <disks> for a domain. For these reasons, it is nicer if the > statistics output always includes minimal information on every > resource being described, with enough to correlate back to host > resources, and even when some statistics are available only on a > running domain. >

> + * "block.<num>.source" - string describing the source of block device <num>, > + * such as the host path of a file or device. Fair enough as long as we document that we only return it for non-network sources. We had quite a few problems with network sources so I'd rather not expose it for those due to possible ambiguity.

> * > * Specifying VIR_CONNECT_GET_ALL_DOMAINS_STATS_ENFORCE_STATS as @flags makes > * the function return error in case some of the stat types in @stats were > - * not recognized by the daemon. > + * not recognized by the daemon. However, even with this flag, a hypervisor > + * may omit individual fields within a group if the information is not > + * available; as an extreme example, a supported group may produce zero > + * fields for offline domains if the statistics are meaningful only for a > + * running domain. > * The code changes are not entirely related to this doc change.

> - QEMU_ADD_NAME_PARAM(record, maxparams, "block", i, disk->dst); > + QEMU_ADD_NAME_PARAM(record, maxparams, "block", "name", i, disk->dst); > + if (disk->src && disk->src->path) && virStorageSourceIsLocalStorage(disk->src)