Jail hot migration

[Michael DeMan]

See inline.

On Sep 10, 2010, at 5:36 AM, Andrew Hotlab wrote:

> 
>> Date: Fri, 10 Sep 2010 16:28:15 +1200
>> From: freebsd at snap.net.nz
>> To: freebsd-jail at freebsd.org
>> Subject: Jail hot migration
>> 
>> Hi guys,
>> 
>> I was lately thinking around jail hot-migration feature where one jail
>> could be moved from one host to another without
>> shutting it down, something like vmotion in VMware world.
>> 
>> The storage layer should be easy with zfs send and receive or some form
>> of shared storage. The tricky part would
>> be a memory copy from one node to another and also the CPU handling.
>> 
>> Anyone has an idea how this could be achieved? I guess it would require
>> a kernel module which could take care of memory
>> reservations and a daemon to copy and incrementally sync the jails
>> memory across.
>> 
>> Then also there is the CPU problem..
>> 
>> Sounds like a fair amount of work and development.
>> 
>> All comments are welcomed!
>> 
> Well, I'm not a developer, but I think that the jail framework surely deservestobe evolved in something more "friendly" from a sysadmin's point of view.
> The architecture is great, and that's just enough to consolidate a lot of workloads,but for some applications there are features (resource containers, offline andonline migration of jails, etc.) that need to be improved to be affordable in aproduction environment.
> I think that a lot of work is getting done (resource container and virtualizationstack projects have ben just sponsored by the FreeBSD Foundation), I do not knowhow much time will take to reach a complete "business-ready" virtualizationframework, neither if they are on the right path, but I'm quite confident, because I'msure that the simplicity of the FreeBSD solution will rule any other virtualizationframework out there.
> As the feature you are asking for, I think that resource containers and offlinemigration should be considered first, because overall they'll have more impact onbusiness environments. Further, I believe that building a hot migration procedureworking with third-party running applications will be a very complex task to achieve,maybe too expensive at this time, compared to the amount of work required.
> That's an interesting argument, I'll be glad if more member of the Community willcontribute with their considerations.
> Sincerely.
> 

Sorry, I'm accustomed to 'top positing' - LIFO - polish notation.

Anyway, yes, is it no the plan that ezjail-admin *MIGHT* be integrated into the FreeBSD core release?  Once that is done, anybody could feel comfortable writing a webmin module to manage jails?