I think this might be more readable if we group options
by the commands. So here is the result. Please read and
tell me what you think.
I put formatted manual here because read diff itself
is almost impossible.
v2:
- update description
- use </> for commands
- various formatting and text nitpicks
| CRIU(8) CRIU Manual CRIU(8)
|
|
|
| NAME
| criu - checkpoint/restore in userspace
|
| SYNOPSIS
| criu <command> [options]
|
| DESCRIPTION
| criu is a tool for checkpointing and restoring running applications. It
| does this by saving their state as a collection of files (see the dump
| command) and creating equivalent processes from those files (see the
| restore command). The restore operation can be performed at a later
| time, on a different system, or both.
|
| OPTIONS
| The options are depending on the <command> criu run with.
|
| Common options
| Common options are applied to any <command>.
|
| -v[<num>|v...]
| Set logging level to <num>. The higer the level, the more output is
| produced. Either numeric values or multiple v can be used.
|
| The following levels are available:
|
| · -v1, -v only messages and errors;
|
| · -v2, -vv also warnings (default level);
|
| · -v3, -vvv also information messages and timestamps;
|
| · -v4, -vvvv lots of debug.
|
| --pidfile <file>
| Write root task, service or page-server pid into a <file>.
|
| -o, --log-file <file>
| Write logging messages to <file>.
|
| --log-pid
| Write separate logging files per each pid.
|
| -D, --images-dir <path>
| Use path <path> as a base directory where to look for dump files
| set.
|
| --prev-images-dir <path>
| Use path <path> as a parent directory where to look for dump files
| set. This make sence in case of increment dumps.
|
| -W, --work-dir <dir>
| Use directory <dir> for putting logs, pidfiles and statistics. If
| not specified, <path> from -D option is taken.
|
| --close <fd>
| Close file with descriptor <fd> before any actions.
|
| -L, --libdir <path>
| Path to a plugins directory.
|
| --action-script <SCRIPT>
| Add an external action script. The environment variable
| CRTOOLS_SCRIPT_ACTION contains one of the actions:
|
| · post-dump run an action upon dump completion;
|
| · post-restore run an action upon restore completion;
|
| · network-lock lock network in a target network namespace;
|
| · network-unlock unlock network in a target network namespace;
|
| · setup-namespaces run an action once root task just been created
| with required namespaces, note it is early stage on restore
| nothing were restored yet except namespaces themselves.
|
| -V, --version
| Print program version and exit.
|
| -h, --help
| Print a commands list and exit. The commands list is very short one
| just for overview and does not match this manual.
|
| pre-dump
| Launches that named pre-dump procedure, where criu does snapshot of
| memory changes since previous pre-dump. Also criu forms fsnotify cache
| which speedup restore procedure. pre-dump requires at least -t option
| (see dump below). Optionally page-server options may be specified.
|
| --track-mem
| Turn on memory changes tracker in the kernel. If the option is not
| passed the memory tracker get turned on implicitly.
|
| dump
| Starts a checkpoint procedure.
|
| -t, --tree <pid>
| Checkpoint the whole process tree starting from <pid>.
|
| -R, --leave-running
| Leave tasks in running state after checkpoint instead of killing
| them. This option is pretty dangerous and should be used if and
| only if you understand what you are doing.
|
| If task is about to run after been checkpointed it can modify TCP
| connections, delete files and do other dangerous actions. So that
| criu itself can not guarantee that the next restore action will not
| fail. Most likely if a user starts criu with this option passed at
| least the file system snapshot must be done with help of post-dump
| script.
|
| In other words, do not use it until really needed.
|
| -s, --leave-stopped
| Leave tasks in stopped state after checkpoint instead of killing
| them.
|
| -x, --ext-unix-sk
| Dump external unix sockets.
|
| -n, --namespaces <ns>[,<ns>...]
| Checkpoint namespaces. Namespaces must be separated by comma.
| Currently supported namespaces: uts, ipc, mnt, pid, net.
|
| --manage-cgroups
| Collect cgroups into the image thus they gonna be restored then.
| Without this argument criu will not save cgroups configuration
| associated with a task.
|
| --tcp-established
| Checkpoint established TCP connections.
|
| --veth-pair <IN>=<OUT>
| Correspondence between outside and inside names of veth devices.
|
| --evasive-devices
| Use any path to a device file if the original one is inaccessible.
|
| --page-server
| Send pages to a page server (see page-server command).
|
| --force-irmap
| Force resolving names for inotify and fsnotify watches.
|
| --auto-dedup
| Deduplicate "old" data in pages images of previous dump. Which
| implies incremental dump mode (see pre-dump command).
|
| -l, --file-locks
| Dump file locks. It is necessary to make sure that all file lock
| users are taken into dump, so it is only safe to use this for
| enclojured containers where locks are not holed by someone outside
| of it.
|
| -M, --ext-mount-map <KEY>:<VAL>
| Setup mapping for external mounts. <KEY> is a mountpoint inside
| container and corresponding <VAL> is a string that will be written
| into the image as mountpoint's root value.
|
| --link-remap
| Allow to link unlinked files back when possible (modifies FS till
| restore).
|
| -j, --shell-job
| Allow to dump shell jobs. This implies the restored task will
| inherit session and process group ID from the criu itself. Also
| this option allows one to migrate a single external tty connection,
| in other words this option allows one to migrate such application
| as "top" and friends. If passed on dump it must be specified on
| restore as well.
|
| --cpu-cap [,<cap>]
| Specify cap CPU capability to be written into an image file.
| Basically if <cap> is one of all, cpu or ins, then criu writes CPU
| related information into image file. If the option is omitted or
| set to none then image will not be written. By default criu do not
| write this image.
|
| restore
| Restores previously checkpointed processes.
|
| --inherit-fd fd[<num>]:<existing>
| Inherit file descriptors. This allows to treat file descriptor
| <num> as being already opened via <existing> one and instead of
| trying to open we inherit it.
|
| -d, --restore-detached
| Detach criu itself once restore is complete.
|
| -S, --restore-sibling
| Restore root task as a sibling (make sense with --restore-detached)
| only.
|
| -r, --root <path>
| Change the root filesystem to <path> (when run in mount namespace).
|
| --manage-cgroups
| Restore cgroups configuration associated with a task from the
| image.
|
| --cgroup-root [<controller>:]/<newroot>
| Change the root cgroup the controller will be installed into. No
| controller means that root is the default for all controllers not
| specified.
|
| --tcp-established
| Restore previously dumped established TCP connections. This implies
| that the network has been locked between dump and restore phases so
| other side of a connection simply notice a kind of lag.
|
| --veth-pair <IN>=<OUT>
| Correspondence between outside and inside names of veth devices.
|
| -l, --file-locks
| Restore file locks from the image.
|
| -M, --ext-mount-map <KEY>:<VAL>
| Setup mapping for external mounts. <KEY> is the value from the
| image (<VAL> from dump) and the <VAL> is the path on host that will
| be bind-mounted into container (to the mountpoint path from image).
|
| --ext-mount-map auto
| This is a special case. If this flag is passed, when an external
| mount is missing from the command line --ext-mount-map <KEY>:<VAL>
| syntax, criu attempts to automatically resolve this mount from its
| namespace.
|
| --enable-external-sharing, --enable-external-masters
| These flags enable external shared or slave mounts to be resolved
| automatically when --ext-mount-map auto is passed.
|
| --auto-dedup
| As soon as a page is restored it get punched out from image.
|
| -j, --shell-job
| Restore shell jobs, in other words inherit session and process
| group ID from the criu itself.
|
| --cpu-cap [<cap>,<cap>]
| Specify <cap> CPU capability to be present on the CPU the process
| is restoring. To inverse capability prefix it with ^. This option
| implies that --cpu-cap has been passed on dump as well, except fpu
| option case.
|
| · all. Require all capabilities. This is default mode if
| --cpu-cap is passed without arguments. Most safe mode.
|
| · cpu. Require the CPU to have all capabilities in image to match
| runtime CPU.
|
| · fpu. Requre the CPU to have comaptible FPU. For example the
| process might be dumped with xsave capability but attempted to
| restore without it present on target CPU. In such case we
| refuse to procceed. This is default mode if --cpu-cap is not
| present in command line. Note this argument might be passed
| even if on the dump no --cpu-cap have been specified becase FPU
| frames are always encoded into images.
|
| · ins. Require CPU compatibility on instructions level.
|
| · none. Ignore capabilities. Most dangerous mode. The behaviour
| is implementation dependent. Try to not use it until really
| required.
|
| One possible need of using this option is when --cpu-cap=cpu
| has been passed on dump then images are migrated to a less
| capable processor and one need to restore this application, by
| default criu will refuse to proceed without relaxing capability
| with --cpu-cap=none parameter.
|
| check
| Tests wheter the kernel support is up to date.
|
| --ms
| Do not check not yet merged features.
|
| --feature <name>
| Check a particular feature. Instead of checking everything one may
| specify which exactly feature is to be tested. The <name> may be:
| mnt_id, aio_remap, timerfd, tun, userns.
|
| page-server
| Launches criu in page server mode.
|
| --daemon
| Runs page server as a daemon (background process).
|
| --address <address>
| Page server IP address.
|
| --port <number>
| Page server port number.
|
| exec
| Executes a system call inside a destination task's context.
|
| service
| Launches criu in RPC daemon mode where criu is listeninп for RPC
| commands over socket to perform. This is convenient for the case where
| daemon itself is running in a privilege (superuser) mode but clients
| are not.
|
| dedup
| Starts pagemap data deduplication procedure, where criu scans over all
| pagemap files and tries to minimalize the number of pagemap entries by
| obtaining the references from a parent pagemap image.
|
| cpuinfo dump
| Fetches current CPU features and write them into an image file.
|
| cpuinfo check
| Fetches current CPU features (ie CPU the criu is running on) and test
| if they are compatible with ones present in image file.
|
| SYSCALLS EXECUTION
| To run a system call in another task's context use
|
| criu exec -t pid syscall-string
|
| command. The syscall-string should look like
|
| syscall-name syscall-arguments ...
|
| Each command line argument is transformed into the system call argument
| by the following rules:
|
| · If one starts with &, the rest of it gets copied to the target
| task's address space and the respective syscall argument is the
| pointer to this string;
|
| · Otherwise it is treated as a number (converted with strtol) and is
| directly passed into the system call.
|
| EXAMPLES
| To checkpoint a program with pid of 1234 and write all image files into
| directory checkpoint:
|
| criu dump -D checkpoint -t 1234
|
| To restore this program detaching criu itself:
|
| criu restore -d -D checkpoint
|
| To close a file descriptor number 1 in task with pid 1234:
|
| criu exec -t 1234 close 1
|
| To open a file named /foo/bar for read-write in the task with pid 1234:
|
| criu exec -t 1234 open '&/foo/bar' 2
|
| AUTHOR
| OpenVZ team.
|
| COPYRIGHT
| Copyright (C) 2011-2015, Parallels Inc.
|
|
|
| criu 0.0.3 05/06/2015 CRIU(8)
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
In this mode we test if target cpu has all features present
in image file but do not require bit to bit match: target cpu
may be a new one with more features present.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
On Wed, Oct 01, 2014 at 05:51:09PM +0400, Pavel Emelyanov wrote:
> > Yes, what you've been expecting?
>
> if (!strcmp(argv[optind]))
> return cpu_cap_check()
>
> or smth like this.
updated. So if it become confusing -- feel free to merge [1;9] and
ping me to resend the rest, or pick up from attachements.
>From 6af96ff63ac82f9566c3cba9c116dc67698c9797 Mon Sep 17 00:00:00 2001
From: Cyrill Gorcunov <gorcunov@openvz.org>
Date: Tue, 30 Sep 2014 18:33:40 +0400
Subject: [PATCH] cpuinfo: Add "cpuinfo [dump|check]" commands
They allow to validate cpuinfo information
without running complete dump/restore actions.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
On dump one uses one or more --ext-mount-map option with A:B arguments.
A denotes a mountpoint (as seen from the target mount namespace) criu
dumps and B is the string that will be written into the image file
instead of the mountpoint's root.
On restore one uses the same --ext-mount-map option(s) with similar
A:B arguments, but this time criu treats A as string from the image's
root field (foobar in the example above) and B as the path in criu's
mount namespace the should be bind mounted into the mountpoint.
v3:
* Added documentation
* Added RPC bits
* Changed option name into --ext-mount-map
* Use colon as key and value separator
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Static linking of the binary criu isn't supported any more.
Reported-by: riya khanna <riyakhanna1983@gmail.com>
Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This option will serve to manage CPU capabilities
to be matched/ignored on restore procedure. At the
moment we introduce 'fpu','all' capability arguments.
By default 'all' is set.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
The links to the versioned libcriu.so.* included $(DESTDIR) and
$(LIBDIR) which will generate wrong links if building criu packages.
Now the links points to the correct file without any path.
For some reason criu.8 was installed with executable permission. Use
'install' with '-m 644' to make sure this does not happen.
Signed-off-by: Adrian Reber <adrian@lisas.de>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Make sure we have a clear message why build it failing, as there are
repeated questions at criu@ mailing list.
Before this patch:
[kir@kirpad Documentation]$ make
GEN criu.8
make: *** [criu.8] Error 127
After:
[kir@kirpad Documentation]$ make
/bin/sh: line 1: xmltos: command not found
make: *** [check] Error 1
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
While timestamps can be handy, they clutter output for normal users.
Let's print them only when verbosity (-v) is increased from default.
Currently, default is 2 (-vv) so for timestamps one should use -vvv
or -v3.
Alternatively, we could introduce a separate --timestamps option.
Personally, I find it more handy for timestamps to be tied to log level.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Current description of -v[vvv] was taken from criu-log.h comments
and describes specific log levels used by pr_* functions. The problem
is -vX includes all previous X-1, X-2... levels. Say, -vvvv description
says "debug only", while in fact it is not "only". Fix accordingly.
Also, removed -v0 description as it is useless. What -v0 in fact does is
it sets the log level to default -- same as if -vXXX is not used.
In addition, change a delimiter between option alternatives from comma
to a vertical bar in criu --help output, to be in line with the rest
of usage output.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It can be handful to check how a man page looks in PDF or Postscript.
Use 'make ps' and 'make pdf' to generate one.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Note to package maintainers:
1 Yes we do support DESTDIR.
2 From packaging scripts, use something like this:
make install DESTDIR=$RPM_BUILD_ROOT PREFIX=/usr
(v2: add PREFIX, install to /usr/local not /usr by default)
(v3: fix criu man section -- it is 8 not 1)
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
1. s/pid 1234/pid of 1234/
2. Remove all those "one should type" or "run".
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
A manual page is formal document, not a chitchat, so use of contracted
forms is not appropriate.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
1. Use *bold* for option names.
2. Separate long and short option by a comma and a space.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
1. Move commands out of OPTIONS subsection.
2. Don't use bulleted list -- definition list (such as in OPTIONS) is
better.
Also follwong -> following
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
It's actually not very complicated. Just do this:
1 For literals (verbal text, such as command or option name) use *bold*
2 For substitutions (variable parameter name) use 'italic'
3 Do not use <angle brackets> at all.
Example:
*-f* 'file'
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This command is for root, so section 8 of manual is
more appropriate than 1.
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
1 It should be COPYRIGHT not COPYING
2 Happy New Year!
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
This is developers documentation, I doubt any user of crui
is interested in that. So let's not build it by default.
It can still be built manually:
make -C Documentation Makefile.build.1
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
I occasionally used assignments instead of
appending manpages for generation. Fix it.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
