itpub上有个比较有趣的关于lvm2划出lv绑定到raw devices的贴子，由于没有相关的环境，没有办法测试这些东西，查了一下10gR2 RAC concept文档，并没有明确说明logical volume for raw devices不支持RAC，可以做RAC的存储介质如下：

■ ASM, which Oracle recommends
■ Oracle Cluster File System (OCFS for linux/windows)
■ A network file system
■ Raw devices

lv的信息在vg的描述区域应该是有的，否则另一节点执行vscan应该是找不到的，即然aix的vg有vgda，那rhel的lvm2相来也是有的。。。

这个LVM2一段文字描述(Sharing LVM volumes)：
LVM is not cluster aware
Be very careful doing this, LVM is not currently cluster-aware and it is very easy to lose all your data.

If you have a fibre-channel or shared-SCSI environment where more than one machine has physical access to a set of disks then you can use LVM to divide these disks up into logical volumes. If you want to share data you should really be looking at GFS or other cluster filesystems.

The key thing to remember when sharing volumes is that all the LVM administration must be done on one node only and that all other nodes must have LVM shut down before changing anything on the admin node. Then, when the changes have been made, it is necessary to run vgscan on the other nodes before reloading the volume groups. Also, unless you are running a cluster-aware filesystem (such as GFS) or application on the volume, only one node can mount each filesystem. It is up to you, as system administrator to enforce this, LVM will not stop you corrupting your data.

The startup sequence of each node is the same as for a single-node setup with vgscan
vgchange -ay

in the startup scripts.
If you need to do any changes to the LVM metadata (regardless of whether it affects volumes mounted on other nodes) you must go through the following sequence. In the steps below ``admin node'' is any arbitrarily chosen node in the cluster. Admin node Other nodes
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Close all Logical volumes (umount)
vgchange -an

vgscan
vgchange -ay