Re: [linux-lvm] LVM extend and shrink at Run time supported file systems

[Zdenek Kabelac <zkabelac@redhat.com>]

Dne 8.8.2013 23:35, selva napsal(a):
> Hi All,
>
> I extended the Linear LVM without Unmounting the Logical Volume. But Most of
> the docs suggest to unmount the LVM in shrink process.

I believe not MOST but EVERY docs suggest this ;)

> 1. Is it possible to shrink the LVM at Runtime (with out Unmount). If yes,
> What is correct way to do it.
>

You can shrink any lvm2 device online - as long as you don't care about data 
on this volume - but somehow I don't think it's matching your case...
In typical case you want to shrink filesystem first.
lvreduce support option '-r'  but for obvious reasons requires umount....


> Also I found in some places that only few file system supports Runtime Extend
> and Shrink of LVM.
>
> 2. What are file systems supports LVM extend and shrink without Unmount

Well - btrfs is known to be capable of online shrink - but in that case you 
don't need lvm2 ;)

None of the filesystems like 'extX', 'xfs', 'reiserfs' could be reduced online.

Zdenek