Live Migration for the masses

This is for discussing general topics about how to use VirtualBox.
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Technologov
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Posts: 3342
Joined: 10. May 2007, 16:59
Location: Israel

Live Migration for the masses

Post by Technologov »

VirtualBox 3.1 teleports in... into the Enterprise. The trouble is that it works only in Enterprises, because VirtualBox 3.1 requires so-called "shared storage", which home users don't have. The next Enterprise feature might be High-Availability (HA).

In my opinion, it may be interesting to live migrate VMs, VM appliances, or applications in home environments too...

Home users "teleport" their workload by using web services, such as GMail. See:
http://www.osnews.com/comments/22557

In my opinion, VirtualBox should have an option to Teleport the disk image too, to be useful for Home Users alike... transferring a 10 Gig image (along with snapshots) is not a big deal over Gigabit Ethernet. (removing a requirement for shared storage)
Additionally this feature must be exposed in the VBox GUI, just like Import/Export appliance (OVF) is.

This will be especially useful for Laptop users.

Would it be possible (or feasible) to make it more Home User oriented ? i.e. migrate VMs together with the VDI ?

As for now, the other products (Xen, Hyper-V, Qemu/KVM Live Migration and VMware VMotion) are also targetted at Enterprise users and also require shared storage... so this is purely theoretical talk.

What do you think of it?

-Technologov
markba
Posts: 99
Joined: 1. Oct 2007, 23:50
Location: The Netherlands

Re: Live Migration for the masses

Post by markba »

Technologov wrote:As for now, the other products (Xen,Hyper-V, Qemu/KVM Live Migration and VMware VMotion) are also targetted at Enterprise users and also require shared storage...
I was a bit disappointed, when I read the documentation around Teleportation, because I was under the impression other products *did* a copy of the VDI. It looks like I'm wrong (I've never dug into this) and VBox is not doing bad at all, at least in comparison with other products.
VBoxTool: VirtualBox automation tools http://vboxtool.sourceforge.net/
costan
Posts: 3
Joined: 3. Dec 2009, 00:44
Primary OS: Linux other
VBox Version: PUEL
Guest OSses: WinXP Linux

Re: Live Migration for the masses

Post by costan »

Hello,

i guess we can mix up the DRBD shared storage emulation (http://www.drbd.org) with virtualbox raw disk drive support to achieve a very complete and enterprise shared storage like experience (given a performance reduction since DRBD just EMULATES the shared storage).

You can sit the emulated disk on the DRBD exported device, set a two-primaries behaviour among the two hosts (we can imagine more than two hosts, but let's start with the simple thing), and start the VM on the first host.

The guest OS will happily perform I/O on the DRBD device as if it were a normal local hdd, and DRBD mirrors everything from the first host to the second host system. Then we start the live migration, and the second host receives the teleporting info and start executing the virtual machine with exactly the same data available to the first system.

Since it's a two-primaries scenario, the second host will send modification done by guest OS to the raw device back to the first host, keeping the actual disc in perfect sync (unless something gets broken, at least).


PROs:
- Simple to understand
- Cheap
- REALLY COOL

Drawbacks:
- Need the replication cable with a fast network (Gigabit Ethernet at least, better a twin Giga)
- Not so simple to implement
- Need for a messagging framework to avoid split brain conditions (heartbeat with no services should run fine)
- Need for a DRDB device for any disc of any machine, and config accordingly. Would lead to a bunch of partition on real devices OR lvm usage and configuration to avoid too much partitions. Easy to break config when number of devices grows, and a bunch of TCP connections on the cable (1 for disc).
- I've not yet tested it... but it should work..
Technologov
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Joined: 10. May 2007, 16:59
Location: Israel

Re: Live Migration for the masses

Post by Technologov »

Any other ideas ?
Technologov
Volunteer
Posts: 3342
Joined: 10. May 2007, 16:59
Location: Israel

Re: Live Migration for the masses

Post by Technologov »

small update
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