CRIU

+Pavel Emelyanov was presenting +CRIU at the recent Linux Con in New Orleans. Here are the slides from the talk, mostly describing project history and current state, and possible CRIU applications.

It was quite obvious, that we could trigger some internal application bugs when doing checkpoint/restore on them. Surprisingly we've faced this only once and on a single box.The problem occurred with tiger-VNC server. If connection gets "broken" for ... [More] a while, dropping packets, and client re-sends a bunch of events "at once", the server stops responding for arbitrary long time.The "connection gets broken" is what we do during dump and restore -- we block TCP connection with iptables in order to repair the connected socket carefully (http://criu.org/TCP_connection). So, after we restore server and "fix" connection back, client side re-sends a bunch of events. It does so since we continue to "work" with the client, it sends these events to server, but TCP stack doesn't get any ack-s on them due to locked connection.When server sees this influx it tries to deal with it, drops many events, extends it's event queue but (!) does not respond back till it thinks it's ready. While we keep working with client server may stay unresponsive. We've seen it being stuck for several minutes.This should be another reason for us to try making the live-migration freeze time extremely small :) [Less]

Hello, everyone!I'm glad to announce the 8th release of the checkpoint-restore tool. Though it was mostly bugfix release, we have added a couple of new features.You can find the changelog at http://criu.org/Download/criu/0.8and get the sourced from ... [More] http://download.openvz.org/criu/criu-0.8.tar.bz2It doesn't require any new kernel stuff, so you can run it on v3.11.This version of CRIU should be the last -RC for the v1.0. I really hope that we'll be able to resolve all the stuff we need within a month.See you in Edinburgh on LinuxCon :) [Less]

A video record of +Pavel Emelyanov 's talk about +CRIU on LinuxPlumbers conference in New Orleans.

There are two APIs for CRIU functionality -- command line and RPC. The latter is provided by the CRIU service launched in the background and listening on a unix socket.Starting from the next release, we'll have an integration of this service into +systemd startup engine. Many thanks to +Shawn Landden for this!

I have used +CRIU  exec at the first time in a real life. Sometimes I forget to connect to the office vpn. If I try to send a mail in such moment, mutt hangs forever on receiving data from a socket. Usually I kill it and write the message again. But ... [More] today I had a big one, so I started to think how to save it. mutt hung on receiving data from a socket, so I decided to close it and criu helped me to do that. mutt returned an error and suggested to postpone the message. Happy end. [Less]

Here is a funny story for ya. Hackers and banks, all that stuff.My colleague +Andrey Wagin went into a bank. While waiting in a queue he was working on his laptop. A security guard in a uniform approached him and asked to turn the laptop off and put ... [More] it away. To a question why he answered that those small characters are scrolling down way too fast! [Less]

If you happen to be in Moscow on the 15 of Feb, consider visiting the Virtualization Meetup where +Andrey Wagin will give a talk about CRIU!

In this hangout our project leader +Pavel Emelyanov will describe the current status of the project, highlighting the recent v1.1 release, and share the project plans for the foreseeable future. He will also answer all those burning questions you were so afraid to ask.

Hello, everyone!First of all, we'd like to thank everyone who joined us on the recent hangout-on-air, where +Pavel Emelyanov talked about CRIU past, present and future. He then promised to make an announcement about CRIU's future as live-migration ... [More] tool, so here it is :)Ladies and gentlemen, meet the P.Haul!Although CRIU is the central part of live migrating a container, doing it all by hands can be quite challenging. So, P.Haul is the project where we try to automate this process. Well, actually we want to live-migrate anything CRIU can dump and restore :) but right now we're focused on containers.Note, that P.Haul is in the early pre-alfa state, one needs to carefully prepare a container to live-migrate it. Nonetheless, p.haul demonstrates the basic ideas of doing it, and we have big plans for its future.We'll keep you updated :) Have fun! [Less]