[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC V9 1/4] domain snapshot terms
>>> On 12/18/2014 at 11:05 PM, in message >>> <1418915119.11882.79.camel@xxxxxxxxxx>, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote: > On Tue, 2014-12-16 at 14:32 +0800, Chunyan Liu wrote: > > Changes to V8: > > * add a document for domain snapshot related terms, they will be > > referred in later documents. > > > > ===================================================================== > > Terms > > > > * Active domain: domain created and started > > > > * Inactive domain: domain created but not started > > As Wei says I think you mean "defined" here, since created and started > are (essentially) synonyms for some toolstacks. > > You'll probably want to define "defined" too for clarity. OK. I'll update. > > > > > * Domain snapshot: > > > > Domain snapshot is a system checkpoint of a domain. It contains > > the memory status at the checkpoint and the disk status. > > > > * Disk-only snapshot: > > > > Disk-only snapshot only keeps the status of disk, not saving > > memory status. > > > > Contents of disks (whether a subset or all disks associated with > > the domain) are saved at a given point of time, and can be restored > > back to that state. On a running guest, a disk-only snapshot is > > likely to be only crash-consistent rather than clean (that is, it > > represents the state of the disk on a sudden power outage); on an > > inactive guest, a disk-only snapshot is clean if the disks were > > clean when the guest was last shut down. > > There is the possibility of doing clean snapshots if a guest agent is > involved to quiesce the disks at the right moment (e.g. I believe qemu > has such a thing, or at least I've seen talks about it being developed > at conferences). Right. Qemu has it. Libvirt qemu driver supports that. > Are you including this possibility or explicitly ruling > it out of scope? Just libxl has no mechanism to quiesce the disks even when domain is paused, I didn't mention this scenario. I can add it. Chunyan > > > * Live Snapshot: > > > > Like live migration, it will increase size of the memory dump file, > > but reducess downtime of the guest. > > > > * Internal Disk Snapshot > > > > File formats such as qcow2 track both the snapshot and changes > > since the snapshot in a single file. > > > > * External Disk Snapshot > > > > The snapshot is one file, and the changes since the snapshot > > are in another file. > > > > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |