[dm-devel] generic wrappers for multi-device FS operations

[Ric Wheeler]

On 03/10/2011 10:28 AM, Hannes Reinecke wrote:
> On 03/09/2011 04:13 PM, Ric Wheeler wrote:
>> On 03/09/2011 09:23 AM, Alasdair G Kergon wrote:
>>> On Tue, Mar 08, 2011 at 10:05:40AM -0800, Wendy Cheng wrote:
>>>> So the "resize" is on the filesystem, not the volume ? The "grow" part
>>>> is probably easy. Unfortunately, the "shrink" may not be easy for some
>>>> of the filesystems:
>>> The LVM situation today works both ways around.
>>>
>>> You can use 'lvresize' with an option to resize the filesystem too,
>>> or use 'fsadm' with an option to resize the LV.  We felt that 'fsadm'
>>> was a more-natural approach: allow the user to resize their filesystem
>>> and automatically adjust the things underneath as necessary.
>>>
>>> Long term, we'd like it to be possible to configure a system for resizing
>>> entire device stacks both top down (fsadm) and bottom up (triggered by
>>> the
>>> appropriate Unit Attention).
>>>
>>> (The current fsadm script was written as a proof-of-concept under the
>>> constraint of just wrapping existing binaries. Of course there are
>>> cleaner
>>> ways to do it when you allow filesystem-specific code.)
>>>
>>> Alasdair
>> Is anyone actively looking at taken it beyond proof of concept?
>>
> I'm working on the kernel-side parts, namely pushing unit attention
> events out to userspace via debugfs.
> There'll be daemon reading those and eventually triggering the
> appropriate action.
>
> We could hold a BoF at LSF or Collab summit, seeing that there is
> quite some interest in these kind of things.
>
> Cheers,
>
> Hannes

I think that the idea of a BOF would be great - probably more room/time at 
collab given the schedule of LSF at this point,

Ric