# why to go with cLVM ? **URL:** \ **Category:** SLES High Availability Extension\ **Created:** [July 2, 2015, 8:49am UTC](https://forums.suse.com/t/why-to-go-with-clvm/27213 "2015-07-02T08:49:09Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![sharfuddin](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@sharfuddin](https://forums.suse.com/u/sharfuddin)\ **Post date:** [July 2, 2015, 8:49am UTC](https://forums.suse.com/t/why-to-go-with-clvm/27213/1 "2015-07-02T08:49:09Z")
if I have a cluster with either: 1 - dual primary drbd setup with cluster-aware file system(ocfs2) or 2 - shared storage with cluster-aware file system(ocfs2) then why I do need the cLVM ? ordinary LVM does not work ? ---
**Author:** ![Jens-U](https://avatars.discourse-cdn.com/v4/letter/j/d78d45/32.png) [@Jens-U](https://forums.suse.com/u/Jens-U)\ **Post date:** [July 2, 2015, 2:12pm UTC](https://forums.suse.com/t/why-to-go-with-clvm/27213/2 "2015-07-02T14:12:07Z")
Hi sharfuddin, [QUOTE=sharfuddin;28618]if I have a cluster with either: 1 - dual primary drbd setup with cluster-aware file system(ocfs2) or 2 - shared storage with cluster-aware file system(ocfs2) then why I do need the cLVM ? ordinary LVM does not work ?[/QUOTE] changing the LVM layout from one of the cluster nodes will not be noticed by the other nodes, until a reboot. If you can live with that (i.e. because you use a single OCFS2 partition on the shared media, and won’t change the partitioning), no cLVM is needed. Regards, Jens ---
**Author:** ![sharfuddin](https://avatars.discourse-cdn.com/v4/letter/s/e274bd/32.png) [@sharfuddin](https://forums.suse.com/u/sharfuddin)\ **Post date:** [July 3, 2015, 10:13am UTC](https://forums.suse.com/t/why-to-go-with-clvm/27213/3 "2015-07-03T10:13:30Z")
> changing the LVM layout from one of the cluster nodes will not be noticed by the other nodes, until a reboot. I get “changing the LVM layout” as modifying the size of VG/LV ? did I get you properly ? > If you can live with that (i.e. because you use a single OCFS2 partition on the shared media, and won’t change the partitioning), no cLVM is needed. Got it ;-). Thanks a lot, you helped me.