Re: [Xen-users] Live migration and drbd

[Rafał Kupka <rkupka+Listy.Xen@xxxxxxxxxxxxx>]

On Mon, Nov 10, 2008 at 10:07:48AM +0100, Rustedt, Florian wrote:
Hello,

> No no,
> 
> that's not right!!
> You definetly need an network-filesystem for drbd primary/primary!

Not for Xen live migration.

> There are TWO systems, that access files for writing and both are not
> running the same kernel ergo doesn't "know", that the other side is
> actually locking/writing a file!

It is explained in http://www.drbd.org/users-guide/ch-xen.html. Xen
needs primary/primary for block device write test during live migration
only.

>From that manual:
"Enabling dual-primary mode is necessary because Xen, before initiating
live migration, checks for write access on all VBDs a resource is
configured to use on both the source and the destination host for the
migration."

> So you need OCFS & co. For doing the file-locking....

If you want concurrent file access from two DomUs -- yes, otherwise no.

Regards,
Kupson 
-- 
Great software without the knowledge to run it is pretty useless.
(Linux Gazette #1)

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