[linux-lvm] What is holding back clustered snapshotting?

[Jonathan Brassow]

On Jan 5, 2010, at 1:11 PM, Madison Kelly wrote:

> Hi all,
>
>  I know that, currently, this isn't supported. Would someone be able  
> to explain or point me at a place to read up on what is holding this  
> feature back? What are the difficulties? Is it just a question of  
> time, or are there certain technical hurdles in the way?
>
>  Thanks for any input!

The solution isn't ridiculously hard.  It has actually been  
implemented a couple times by me and at least once by Mikulas  
leveraging a locking interface I had proposed.  (You can search the  
various dm-devel archives for them.)

Our current priority is to improve the snapshot implementation (shared  
snapshots), but cluster snapshots is on the todo list.  It does tend  
to be a matter of time.  As I said, a couple implementations have come  
forward, but it requires a team effort to push it upstream - the  
priority hasn't been high enough for it to surpass other things on the  
list.

  brassow