Description of problem: The flag VIR_MIGRATE_PAUSED is confusing, which is described in https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainMigrateFlags as below: VIR_MIGRATE_PAUSED = 32 (0x20; 1 << 5) Leave the domain suspended on the destination host. virDomainResume (on the virDomainPtr returned by the migration API) has to be called explicitly to resume domain's virtual CPUs. Does that mean if an migration finishes, the vm on the destination will in 'paused' status? Or during the whole migrating process, the vm will keep in 'paused' status, even if it fails? And does the migration here include live migration? The flag VIR_MIGRATE_PAUSED needs more context to help user understand.
(In reply to luyao.zhong from comment #0) > Description of problem: > > The flag VIR_MIGRATE_PAUSED is confusing, which is described in > https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainMigrateFlags > as below: > > VIR_MIGRATE_PAUSED = 32 (0x20; 1 << 5) > Leave the domain suspended on the destination host. virDomainResume (on the > virDomainPtr returned by the migration API) has to be called explicitly to > resume domain's virtual CPUs. > > > Does that mean if an migration finishes, the vm on the destination will in > 'paused' status? Yes. > Or during the whole migrating process, the vm will keep in > 'paused' status, even if it fails? It migration fails, the domain on the destination will be cleaned up, so there is nothing to be left suspended. Also, for pausing domain during migration it's sufficient to not specify VIR_MIGRATE_LIVE flag. > And does the migration here include live > migration? > > The flag VIR_MIGRATE_PAUSED needs more context to help user understand. Can you shed more light into this? What would you think the description should look like?
@mprivozn IMHO, we can describe what's the domain's status after migration fails/succeeds, and which kind of migration is controlled by this flag, cold migration or live migration?
(In reply to luyao.zhong from comment #2) > @mprivozn > > IMHO, we can describe what's the domain's status after migration > fails/succeeds, and which kind of migration is controlled by this flag, cold > migration or live migration? I think the flag is orthogonal to live/cold migration. In both cases (cold/live) the guest vCPUs will be suspended (in case of cold migration for the whole duration of migration, for live migration only for a brief moment when QEMU is switching control over to the destination). Regardless, this flag controls whether vCPUs should be resumed on the destination or left suspended. Anyway, feel free to suggest new wording (or even post it as a patch). I would do it, but I'm sorry, I don't see the problem.
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