Re: [Xen-users] synchronization with AoE

[Daniel Bareiro <daniel-listas@xxxxxxx>]

On Sunday, 03 December 2006 13:24:21 +0800,
Tim Post wrote:

> > I'm using AoE to export a ReiserFS partition that contains a
> > file-backed VBDs of a DomU to perform tests of migration between two
> > xen host. The three systems have Debian GNU/Linux Etch.
 
> You'd do better off using LVM backed VBD's and exporting them
> individually.

What do you refer with *individually*?

I thought to export a partition (PV) using vblade. This partition
contains the LV of the domU's FS. Then, in the Xen hosts, I import the
device using aoe module/vgscan/vgchange -a y. Now then, as long as the
simultaneous mounting ---to perform the migration--- in the two Xen host
can corrupt the FS, must I put the device in the domU config file?
Something like:

disk = [ 'phy:vg_xen/lv_vm1,hda1,w' ]

Maybe, another choice is to use losetup to associate a loop device with
the file-backed VBD of DomU. Then, we export the loop device. I guess
that the VBD configuration lines would change to:

disk = [ 'phy:etherd/e0.0,hda1,w' ]

Is it correct?

> > Both writes and deletes of files in the file-backed VBD DomU works
> > synchronized, but the problem seems to be when I want to create a
> > file in the exported partition together with the file-backed VBDs
> > DomU. In this case, doesn't seem syncronize with the rest of the
> > both import and export servers. 
 
> Again, you can not mount (in rw mode) *any* partition that is not
> formatted as a cluster file system from two computers.

Do you know if the kernel provided for Xensources supports the cluster
file systems that you've mentioned? This file systems must be used
together with AoE as well? What about csync2 [1]?

> > Is it possible to perform this writes and deletes in synchronized
> > mode too?

> I'd just make smaller volume groups, and copy over the loops to their
> respective new homes (the smaller VG's). 

Do you refer to copy the content of the file-backed VBD to a LV into the
VG?

Thanks for your answer.

Regards,
Daniel

[1] http://oss.linbit.com/csync2/
-- 
Daniel Bareiro - System Administrator
Fingerprint: BFB3 08D6 B4D1 31B2 72B9  29CE 6696 BF1B 14E6 1D37
Powered by Debian GNU/Linux Etch - Linux user #188.598

Attachment: signature.asc
Description: Digital signature

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