[Devel] [ANNOUNCE] OpenVZ releases checkpointing/live migration of processes

[Kir Kolyshkin]

Jun OKAJIMA wrote:

>>OpenVZ team is proud to announce the release of the new 
>>checkpointing/restore feature. This feature allows to save (checkpoint) 
>>and restore the whole state of a Virtual Environment (VE, container) and 
>>do a live migration of a VE to another physical box while preserving 
>>process states and TCP/IP connections.
>>
>>During live migration the in-kernel state of processes and their 
>>resources (including memory, registers, IPC, pids, open files, sockets, 
>>etc.) is saved and then restored on another machine. Since all network 
>>connections are preserved with all the in-progess requests, user doesn't 
>>experience interruption of service.
>>
>>[....skipped....]
>>
>One Question ---.
>
>Xen needs iSCSI or alike for a FS when you want to do a live migration,
>because it needs very same inode mapping.
>How about this issue on OpenVZ?
>  
>
We do not have any special hardware requirements for live migration. 
I.e. your laptop will work fine.

>For example, can I migrate a VE to a server which has same file tree on
>its HDD, but has different FS type and inode number?
>
Yes you can; we just use rsync prior to freezing a VE to copy VE's files 
to the destination node, and another rsync after VE freeze.