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fixed sections; rewording
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−== External Checkpoint Restore ==+
−=== Command Line Options ===+==== <code>--root</code> ====+==== <code>--ext-mount-map</code> ====+==== <code>--manage-cgroups</code> ====+==== <code>--evasive-devices</code> ====+==== <code>--inherit-fd</code> ====+=== Restore Prework for External C/R ===+=== An External C/R Example ===+=== External C/R Helper Script ===+
{{Warning|External C/R was done as a proof-of-concept. Do not use it; please see [[Docker]] for a proper way to do checkpoint/restore with Docker. This article is kept here for historical purposes and some background info.}}
−{{Note| External C/R was done as proof-of-concept. Its use is discouraged and the helper script mentioned below may break in the near future.}}
This approach is called external because it's happening external to the
This approach is called external because it's happening external to the
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include the Docker daemon which runs in the global PID namespace.
include the Docker daemon which runs in the global PID namespace.
−== Command Line Options ==
In addition to the usual CRIU command line options used when
In addition to the usual CRIU command line options used when
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line options are needed for Docker containers.
line options are needed for Docker containers.
−=== <code>--root</code> ===
This option has been used in the past only for restore operations
This option has been used in the past only for restore operations
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be necessary to specify this option anymore.
be necessary to specify this option anymore.
−=== <code>--ext-mount-map</code> ===
This option is used to specify the path of the external bind mounts.
This option is used to specify the path of the external bind mounts.
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at <code>/var/lib/docker/containers/''container_id''/hostname</code>.
at <code>/var/lib/docker/containers/''container_id''/hostname</code>.
−=== <code>--manage-cgroups</code> ===
When a process tree exits after a checkpoint operation, the cgroups
When a process tree exits after a checkpoint operation, the cgroups
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re-creating them if necessary.
re-creating them if necessary.
−=== <code>--evasive-devices</code> ===
Docker bind mounts <code>/dev/null</code> on <code>/dev/stdin</code> for detached containers
Docker bind mounts <code>/dev/null</code> on <code>/dev/stdin</code> for detached containers
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the global <code>/dev/null</code> and the container <code>/dev/null</code> as the same device.
the global <code>/dev/null</code> and the container <code>/dev/null</code> as the same device.
−=== <code>--inherit-fd</code> ===
For native C/R support, this option tells CRIU to let the restored process "inherit"
For native C/R support, this option tells CRIU to let the restored process "inherit"
its specified file descriptor (instead of restoring from checkpoint).
its specified file descriptor (instead of restoring from checkpoint).
−== Restore Prework for External C/R ==
Docker supports many storage drivers (AKA graph drivers) including
Docker supports many storage drivers (AKA graph drivers) including
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filesystem again before attempting to restore.
filesystem again before attempting to restore.
−== An External C/R Example ==
Below is an example to show C/R operations for a shell script that
Below is an example to show C/R operations for a shell script that
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</pre>
</pre>
−== External C/R Helper Script ==
As seen in the above examples, the CRIU command line for checkpointing and
As seen in the above examples, the CRIU command line for checkpointing and
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</pre>
</pre>
+== See also ==
+
+* [[Docker]]
[[Category:HOWTO]]
[[Category:HOWTO]]