Hi,

I'm quite confuse with lvm2 an clvm packages on gentoo amd64.

I have 2 xen-hosts domains0 using the same volume group (vg) including  
logical volumes (lv) for the domainsU. The physical volume is on 2 SAN  
(using raid1 lvm on logical volumes) with dual path. I use multipath- 
tools to access the right path (access are active/enabled only).

So my domains0 have 4 access on storage system (2 on each volume, one  
volume on each SAN). With multipath-tools I choose only one path per  
volume. With LVM I have created some raid1 logical volumes on the 2  
san-volumes I see on my hosts domain0. Each xen domainsU has access to  
one lvm logical volume, but I need to have these logical volumes ready  
to use on the second xen-server domain0 (for failback). So I need to  
use a locking system to use my lvm volume group on the 2 domain0, right?

If I want to install clvm, the package is masked and "flagged in read  
me" as "redondant" with lvm2. In lvm2 I can't get "clvm" flag to work  
(it is in parentheses).
My packages versions are the stables ones :
sys-fs/lvm2-2.02.36
sys-fs/multipath-tools-0.4.7-r2 (0.4.8 doesn't work)
sys-kernel/xen-sources-2.6.18-r12

Do I need clvm? What must I do to having it working?

Another question. With recent versions of lvm2, I need to uninstall  
device-mapper. How can I do it when multipath-tools depends on device- 
mapper??

Best regards

David