Thanks a lot for all the answers. Please see my comments inline.
>> When disk is file based , it is possible. >> When its normal disk and have some file system like ZFS or volume >> manager which supports snapshot , it's possible.Otherwise its not >> When its LUN from filer , if filer has snapshot capabilities , it is >> supported. otherwise not. > You are correct. For disk image snapshot, this depends on the capability > of the backend storage where the disk image is stored. The easiest solution > is to store disk images with ZFS and you will have quick snapshot features. > hmm .. wondering when the disk is actually a file. Even in that case LDom does not support snapshot. I still need to use some other tool to get the snapshot of the 'virtual disk' file ? I understand now this will be the case for normal disk or LUN device exported from filer. But for file ? > Note that when you snapshot a disk image, you only take a snapshot of > the virtual disk, this does not include the domain configuration or the > memory state. > Ok .. got it. So we do not really snaps the Ldom instance per say but only the devices that it might be using. >> Also my question would be, does LDom admin tool takes care of these >> snapshot work in the back end? Or it is the user's responsibility >> to manage all these different snapshots. > > This has to be done manually. > Are there are any open source tools known which can integrate with(work with) LDom to create snapshot if devices can be snapped using some some technology.(file NetApp filer can be snapped, some volume managers can take snapshot). I know this has to happen independently but just wondering if anybody has already solved this problem. >> 3: What is the preferred way to take LDom snapshots in community ? > > Use ZFS to store disk images (either on ZFS filesystem or volume), then > use 'zfs snapshot/clone'. This is frequently used to clone an existing > domain to create a new one. > Am I correct in assuming 'Even in case of ZFS , snapshot of disk will be to be taken manually and will not be controlled by LDom admin util ' ? >> 4:Does Ldom have suspend and resume support at machine level ? > > There's a suspend/resume feature but it can not be used directly. It is > used by warm migration. During warm migration, a domain is going to be > suspended, its memory and cpu state is going to be transfered to another > platform where it will be resumed. > But there's currently no option to use this feature to suspend a > domain to disk. > You mean in warm migration cpu state and memory state is transferred directly to target LDom instance and there is no way for now to dump that info to disk. hmm Is there any plan to add such support in near future ? >> 5: Is there any way for third party application to access these >> snapshots and memory state ? Is there any too/library which provides >> interface for accessing such snapshots and other machine state (e.g >> memory in case of hibernation). Any links ? > So if its ZFS or some volume manager , corresponding tools are the only thing we need to use to create snapshot and back them up somewhere else and there is no generic api/tools which cover all these different technologies(filer/ZFS/file based) under on hood rht ? Thanks, Rohit
