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

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

[selva]

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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.

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

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

Regards
Selva

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

[Zdenek Kabelac]

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