[dm-devel] /dev/dm-N and Veritas?

[Christophe Varoqui]

On lun, 2005-10-31 at 15:04 -0500, Bruen, Mark wrote:
> I would like to use "device mapper" for multipathing which I have setup 
> and Veritas Volume Manager for Virtualization. I normally  create LUNs 
> on the SAN and they show up as /dev/sdX, /dev/sdY, etc... I initialize 
> them for use with Veritas Volume Manager which allows me to expand 
> filesystems across multiple LUNs, create snapshots, split disks off for 
> deporting, etc...
> I have many years of Veritas experience and none with LVM so I would 
> (for now anyway) like to use the multipathed devices /dev/dm-N with 
> Veritas. Is it possible?
> Thanks.
>     -Mark
> 
There are some issues in this field : /dev/dm-* might or might not
exist, might be duplicate of /dev/mapper/ entries, paths appear
as /dev/sd* nodes and are not hidden.

The Volume manager has to deal with these things. Even LVM2 has rough
edges here. I would guess VxVM may have a hard time too.

That said, this question will ultimately have to be responded by
Veritas. I can image them saying that you'd better use *their*
multipathing solution, being well integrated with the volume manager.

The DM multipathing is easily disabled.

Regards,
cvaroqui