WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

RE: [Xen-users] Distributed xen or cluster?

To: xen-users <xen-users@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-users] Distributed xen or cluster?
From: "Joseph L. Casale" <JCasale@xxxxxxxxxxxxxxxxx>
Date: Wed, 21 Jan 2009 19:28:52 -0700
Accept-language: en-US
Acceptlanguage: en-US
Delivery-date: Wed, 21 Jan 2009 18:29:46 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <200912118621.185742@leena>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <7207d96f0901211547o6cc87658t6f0115494b1ef2d6@xxxxxxxxxxxxxx> <200912118621.185742@leena>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: Acl8JVxmO8qIm7bETwKRosRkOieXiAAEscLg
Thread-topic: [Xen-users] Distributed xen or cluster?
>> I think you misunderstood. Live migration of a domU with 1G memory
>> might take a minute or two, but the actual downtime is about a SECOND
>> or two :D
>
>I'll have to play with this. The problem is that on a failure, you never know 
>when the server is going to go down. Makes me wonder if I could have a simple 
>script going which constantly sends the >updates to a shared drive and some 
>heartbeat mechanism on standby machine/s so that if main server goes down, 
>another quickly takes over.
>
>Wonder if that's the idea behind the link that Rob sent me. No need to 
>re-invent the horse, looks like there are in fact lots of ideas out there.

You are expecting to make "an instance of a vm" fault tolerant. I haven't seen
that, but I have seen storage fault tolerant as people have stated. So you still
are concerned with the xen server tanking (which makes redundant storage 
useless)
you need to handle this at the application level. Such as fault tolerant 
service's
running on two xen servers with their each own vm.

VirtualServerA on XenServer1 running some cluster aware application that *you* 
need
redundant with VirtualServerB on XenServer2.

Many applications and OS's have this feature, Windows Clusters etc. You could 
cluster
a file server this way so the backend is redundant and the file serving 
application is
redundant. Clients then access a virtual host that is created by the cluster 
software
running on the two vm's...

jlc

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users