[Linux-cluster] Xen Live Migration and iSCSI

[Lon Hohberger]

On Fri, 2006-11-10 at 20:14 +0000, Robert Hatch wrote:
> Hi, I am configuring a Xen high availability solution which backs onto a
> SAN via iscsi.  I am not sure whether to allow the domU's to swap
> locally on the dom0 or have a separate swap partition on the san.  My
> main question is: When you perform a live migration are the contents of
> the RAM and the swap transferred to the new dom0 or is it just the ram
> that is transferred? 

I'm pretty sure it's RAM only; you need to have the swap partition
shared between the nodes (on the SAN).  If you're not doing live
migration, then whether the swap disk is on the SAN or not is your
choice.

> If both are then wouldn't it be best to have local swapping so that the
> new state is built on the new node.  Would this also be faster as there
> would be fewer loads on the san in the long term?

Even if it does copy the swap disk, I suspect a well engineered SAN will
almost always outperform a local hard disk anyway.  *shrug*

-- Lon