Hi,
Well if you have the VM's on a SAN like yours, you can build some form of HA.
As was said before, when a heartbeat to a domU or even an entire
machine fails, you mark the VM's on it as down and reboot them from
another server using the cLVM backed storage.
Citrix Xenserver does this magic behind a little GUI and very little
work for you.
Having a proper SAN is half the battle, then it's the setup.
And yes, for a highly available environment you need several servers.
As for doing maintenance on a machine, yes manually migrating all the
VM's might be a bit of a pain.
You should really have some kind of script in place to "evacuate" the
node, which just migrates all the nodes.
live migration or otherwise (again with the SAN architecture all you
need is a reboot)
Regards,
Barry
On Tue, Jan 20, 2009 at 5:25 PM, lists@xxxxxxxxxxxx <lists@xxxxxxxxxxxx> wrote:
>> Exactly what kind of redundancy are you looking for? Is it (for
>> example) having several domUs serving the same web content and having
>> a load balancer in front of them so traffic is balanced among working
>> domUs?
>
> Here's a small example.
>
> I have a GFS cluster of servers which serve up LAMP services which uses two
> LVS (redundant) servers as a front end for load balancer. Each server has a
> fibre channel card to attach it to the FC network so that it can see the GFS
> volumes as it's own. It's a pretty nicely redundant service, if one server
> fails, nothing goes down, things just keep on running. The one problem I
> haven't bothered with is that if there is a failure, the user has to
> reconnect because the session gets messed up. Otherwise, it's fully redundant.
>
> With my virtualization testing, things aren't so much fun. When a server goes
> down, or needs to be rebooted, or anything which causes it to have to be
> down, all guests on that server go down with it of course. Migrating over to
> another machine is pointless because it takes way too much work to migrate
> just to reboot a server.
>
> Of course, what would be best would be proper redundancy, so that there are
> multiple containers working together as one. If one goes down, the others
> simply keep going and no servers go down.
>
> I have no idea how I'll deal with win servers because they tend to need
> stupid re-activating when moved to different hardware, at least the limited
> experience I've had so far. Either way, that's not an issue because most of
> the servers, if not all, are going to be Linux.
>
> I've not done anything with this yet because I'm fairly new to virtualization
> but even new, I have quickly realized that this is very badly needed. I've
> started with VMware Server 2.0, was about to migrate over ESX but decided it
> was time to try xen.
>
> So, I'm looking for a way to have proper redundancy, not just migration
> because that's not an option when you just need to reboot or take a server
> down for some reason.
>
> I'll post another question about storage separately so that this thread
> doesn't become too convoluted.
>
> Mike
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users
>
--
Barry van Someren
---------------------------------------
Email: barry@xxxxxxxxxxxxxxx
Email: goltharnl@xxxxxxxxx
Linked in: http://www.linkedin.com/in/barryvansomeren
KvK: 27317624
WWW: http://java-monitor.com/forum/index.php
_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users
|
Home