Hi, if i am doing the following: xm create myvm xm save myvm state.dat xm create myvm (now logging on an do some modifikations) xm destroy myvm xm restore state.dat Will that leave the filesystem consistent? Do i have a filesystem that is the same like the one at the point of the saving? Is there a way to take a snapshot of a virtual machine for later staterestoring instead of shuting the machine down and copying its imagefile? Thanks, Julian _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Julian Hagenauer wrote:> xm create myvm > xm save myvm state.dat > xm create myvm > (now logging on an do some modifikations) > xm destroy myvm > xm restore state.dat > > Will that leave the filesystem consistent? Do i have a filesystem that is the same like the one at the point of the saving? > Is there a way to take a snapshot of a virtual machine for later staterestoring instead of shuting the machine down and copying its imagefile? > >I thought about the same too and my conclusion was: Since ''xm save'' saves the memory and the state of the machine, but not the disk, any changes on the disk and on swap space is bad. However, if you do ''xm save'', then do a snapshot from disks (including swap), then ''xm create'' again (which will have an unclean filesystem just like after a crash), then ''xm destroy'' and then undo all the recent changes on disk and swap (undo snapshot), THEN you can ''xm restore'' that state again. Since memory is in the state.dat, and disk is unchanged (curtesy of lvm snapshots), that''s ok. That is, if lvm snapshots work as expected. From what I gather on the web and several mailing lists, it''s still marked as ''experimental'' for a reason. If you happen to have fancy hardware which can do snapshots in a reliable way, I see no problem. Harald _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi> > xm create myvm > > (now logging on an do some modifikations) > > xm destroy myvm > > xm restore state.dat> Since ''xm save'' saves the memory and the state of the > machine, but not the disk, any changes on the disk and on > swap space is bad.I think the same.> However, if you do ''xm save'', then do a snapshot from disks > (including swap), then ''xm create'' again (which will have an > unclean filesystem just like after a crash), then ''xm > destroy'' and then undo all the recent changes on disk and > swap (undo snapshot), THEN you can ''xm restore'' that state again. > Since memory is in the state.dat, and disk is unchanged > (curtesy of lvm snapshots), that''s ok.But it will not fullfill the purpose of "do some modifikations". Regards, Steffen _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users