On Fri, 2009-04-17 at 05:48 -0400, Oren Laadan wrote: > You mean an sshd with an open connection probably; the server itself > is clearly useful to be able to c/r. > Yes I mean C/R of sshd with active connections. > > A canonical example would a virtual-private-server: instead of doing > server consolidation with a virtual machine, your do with containers. > In a sense, containers lets you chop the OS into independent isolated > pieces. You ca use a linux box to run multiple virtual execution > environments (containers), each running services of your choice. They > could range from a sshd for users, to apache servers, to database > servers to users' vnc sessions, etc. > Indeed, containers allow to implement VPS just like virtual machines: we call them system containers. Not much to say about that since they don't introduce new concepts to users. > Now comes the that you really need to take the machine down, for > whatever reason. With c/r of live connections you can live-migrate > these containers to another machine (on the same subnet) that will > "steal" the IP as well, and voila - no service disruption. > Theorically, yes. Practicaly, you need a lot more than *simply* capturing and restoring socket states for such a migration to be usable in the real world. > > Such scenarios are the focus of Alexey. > So Alexey should provide some realistic examples, with several hosts, routers, switches and overall network infrastructure. > I'm also very interested in these scenarios, and I'm _also_ thinking > of other scenarios, where either (a) an entire container is not > necessary (example: user running long computation on laptop and wants > to save it before a reboot), or (b) the program would like to make > adjustments to its state compared to the time it was saved (example: > change the location of an output log file depending on the machine > on which your are running). > I'm _only_ interested in these other scenarios for the moment. > Unfortunately, if we plan for and require, as per Alexey, that c/r > would only work for whole-containers, these two cases will not be > addressed. > Discussion must go on then. There's no hurry in getting C/R mainlined. :) -- Gregory Kurz gkurz@xxxxxxxxxx Software Engineer @ IBM/Meiosys http://www.ibm.com Tel +33 (0)534 638 479 Fax +33 (0)561 400 420 "Anarchy is about taking complete responsibility for yourself." Alan Moore. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
