Re: Resizing LVM partitions

[Miroslav Skoric <skoric@uns.ac.rs>]

On 1/22/24 6:59 PM, tomas@tuxteam.de wrote:
> On Mon, Jan 22, 2024 at 03:40:06PM +0000, Alain D D Williams wrote:
> > On Mon, Jan 22, 2024 at 10:29:55AM -0500, Stefan Monnier wrote:
> > > > lvextend --size +1G --resizefs /dev/mapper/localhost-home
> > > >
> > > > Ie get lvextend to do the maths & work it out for me.
> > > >
> > > > Those who are cleverer than me might be able to tell you how to get it right
> > > > first time!
> > >
> > > lvreduce --size -50G --resizefs /dev/mapper/localhost-home
> >
> > Oh, even better. It is a long time since I looked at than man page.
> >
> > Does this still need to be done with the file system unmounted or can it be
> > done with an active file system these days ?
>
> You have first to shrink the file system (if it's ext4, you can use
> resize2fs: note that you can only *grow* an ext4 which is mounted
> (called "online resizing) -- to *shrink* it, it has to be unmounted.

I will check it again but I think that file systems in that LVM are 
ext3. So it requires all of them to be unmounted prior to resizing ?

> Since I wasn't quite sure whether ext2's Gs are the same as LVM's
> and didn't want to bother with whatever clippings each process
> takes, what I did in this situation was:
>
>   - shrink (resize2fs) the file system to a size clearly below target
>   - resize the LVM to my target size
>   - resize2fs again without params, which lets it take whatever the
>     partition offers

That last resize2fs (without params) would not work here, or at least it 
would not work for my three file systems that need to be extended: / , 
/usr , and /var . Maybe to extend each of them separately like this:

lvextend --size +1G --resizefs /dev/mapper/localhost-root
lvextend --size +1G --resizefs /dev/mapper/localhost-usr
lvextend --size +1G --resizefs /dev/mapper/localhost-var

?