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What cannot be checkpointed (edit)

Revision as of 08:02, 21 September 2016

312 bytes removed , 08:02, 21 September 2016

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By default CRIU allows to dump the set of processes and their resources if this set has no connections outside. However, in some situations it makes sense to ignore this external connection on dump and recreate one on restore. So, what this "connection outside" is? For example:

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* '''UNIX socket'''. Application may have a UNIX socket connected to some other app and the latter one is not dumped. This is called [[external UNIX socket]].

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''Main article: [[External resources]]''

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* '''TTY, group and session'''. If you start a program from shell, the tty, process group and session of the new program can be shared with the shell itself. People often meet this when they try CRIU for the first tome on a [[simple loop]].

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* '''[[TCP connection]]'''. This socket is literally an external connection, so CRIU should be explicitly allowed to dump one.

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* '''[[External ~~bind mounts~~]]'''

=== File locks ===

A file lock is an object, that belongs to some filesystem. On dump it's impossible to find out whether this lock help by one task ''can'' be used by some other. Thus, CRIU doesn't dump tasks with held locks. The <code>--file-locks</code> CLI option tells CRIU to dump the lock.

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''Main article: [[File locks]]''

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=== Invisible files ===

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Sometimes a file name cannot be found in a filesystem. In this case criu can leave a temporary name for it.

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''Main article: [[Invisible files]]''

== Cannot be dumped (yet) ==

Xemul

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