Re: How to remount btrfs without compression?

[Lubos Kolouch <lubos.kolouch@gmail.com>]

Dmitry Olenin, Wed, 09 Nov 2011 17:03:39 +0900:

> On 11/09/2011 04:48 PM, Lubos Kolouch wrote:
>> Sorry for possibly OT question - when I have historical btrfs system
>> mounted with zlib compression,
>>
>> can I remount it with lzo ? What will happen? Will the COW be broken
>> and the files taking duplicate space? Or will the Universe explode and
>> be replaced with something even more bizzare?
> 
> Hello Lubos If you have a kernel that supports lzo (don't quite remember
> when it got in), why can't you?
> Absolutely nothing will happen, and only the new/updated files will be
> with lzo compression. You can remount on the fly switching b/w the two
> compression options without any problems.

Hello Dmitry,

By the way, this is interesting question to me - I mounted the filesystem
with -o compress=lzo, in dmesg showed btrfs: use lzo compression,

but - the lzo module was not loaded (not shown in lsmod - and yes, I have
it as a module).

When I do modprobe lzo, it shows there.

Isn't it a bit strange? So btrfs is using lzo module that was not loaded?
(and says so in the dmesg output)?

Thank you

Lubos