lxc-checkpoint, lxc-restart in the LXC source tree are currently stubs. Following set of patches, when applied to LXC and built with USERCR as described below, enable enable lxc-checkpoint and lxc-restart of some simple containers TODO: - Determine if lxc_checkpoint needs a --container option (see TODOs in src/lxc/checkpoint.c) - This patchset was tested using lxc-nonetns.conf. I ran into a problem creating a bridge with lxc-veth.conf and lxc-macvlan.conf. I have not debugged the problem with VNC and lxc-macvlan.conf. - 'global_send_sigint' is still a global variable in USERCR. We need to define a better interface to expose its functionality to callers of app_restart(). - Choose better names and API for USERCR :-) - Additional TODOs specific to checkpoint/restart are listed in their specific patches. Changelog[v3]: Changed following based on feedback from Michel Normand, Daniel Lezcano and others. - Added --with-libcr configuration option to specify the path to usercr (see usage below). - lxc-checkpoint now implicitly freezes before and unfreezes after checkpoint. - Implemented the --pause options to lxc-checkpoint and lxc-restart and the --kill option to lxc-checkpoint. - Ported to ckpt-v20-dev (required adding CHECKPOINT_NONETNS flag to app_checkpoint() to work around) Changelog[v2]: (Based on feedback from Oren Laadan, Serge Hallyn, Daniel Lezcano and Cedric Le Goater) - Rather than drop --directory option to lxc_checkpoint/lxc_restart add a new option (--image). - Integrate lxc_checkpoint to work with USERCR - USERCR renamed usercr.h to "app-checkpoint.h" - USERCR does not create/install libcheckpoint.a and usercr.h for now. So link directly with app-checkpoint.h, restart.o and checkpoint.o - USERCR renames the interfaces to app_checkpoint() and app_restart() 'struct app_checkpoint_args' 'struct app_restart_args'. USAGE: 1. Build USERCR $ cd /root $ git-clone git://git.ncl.cs.columbia.edu/pub/git/user-cr.git user-cr $ cd user-cr $ git-checkout ckpt-v20-dev Tested with commit e275f77e4a82d228c1df14dbeb691342e32cdac2 as HEAD. # Apply following two patches: https://lists.linux-foundation.org/pipermail/containers/2010-March/024037.html https://lists.linux-foundation.org/pipermail/containers/2010-March/024038.html $ cd /root/user-cr $ KERNELSRC=/root/linux-2.6/ make Build USERCR by pointing to corresponding kernel-source. This should create restart.o and checkpoint.o needed by LXC. 2. Build/install LXC $ cd /root/lxc.git Apply attached patches to LXC (I tested with these patches applied to commit 9ea8066aa67b808f71f46e346bd7a215e2a355f3) $ autogen.sh $ ./configure --with-libcr=/root/user-cr This will fail if /root/user-cr does not container checkpoint.o, restart.o and app-checkpoint.h files $ make $ make install 3. Checkpoint/restart a simple LXC container $ lxc-execute --name foo --rcfile lxc-no-netns.conf -- /bin/sleep 1000 $ lxc-checkpoint --name foo --image /root/lxc-foo.ckpt $ lxc-stop --name foo $ lxc-restart --name foo --image /root/lxc-foo.ckpt 4. Checkpoint/restart other LXC containers such as: - a file-io session (see run-fileio1 in cr-tests[1]) - process-tree (see run-ptree1 in cr-tests[1]) - A vi session inside a VNC Server using "twm". i.e $ cat /root/.vnc/xstartup #!/bin/sh xsetroot -solid grey vncconfig -iconic & xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" & twm & $ lxc-execute --name foo --rcfile lxc-no-netns.conf -- \ /usr/bin/vncserver :1 $ vncviewer :1 # Open a vi session $ lxc-checkpoint --name foo --statefile /root/vnc.ckpt $ lxc-stop --name foo $ lxc-restart --pause --name foo --statefile /root/vnc.ckpt # Leaves the server frozen due to --pause $ lxc-unfreeze --name foo $ vncviewer :1 # Should bring up the old VNC session with vi window [1]: cr-tests: git://git.sr71.net/~hallyn/cr_tests.git Signed-off-by: Sukadev Bhattiprolu <sukadev@xxxxxxxxxxxxxxxxxx> _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
