From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chunyan Liu Subject: [RFC V10 1/4] domain snapshot terms Date: Mon, 26 Jan 2015 11:25:10 +0800 Message-ID: <1422242713-3744-2-git-send-email-cyliu@suse.com> References: <1422242713-3744-1-git-send-email-cyliu@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1422242713-3744-1-git-send-email-cyliu@suse.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: wei.liu2@citrix.com, jfehlig@suse.com, ian.jackson@eu.citrix.com, Ian.Campbell@citrix.com, Chunyan Liu List-Id: xen-devel@lists.xenproject.org ===================================================================== Terminology * Active domain: domain created and started (also referred as "live") * Inactive domain: domain created but not started (also referred as "offline") * 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. * 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.