Hello

I want to extend size of my lv /var/ partition.
But first i had to resize (shrink) root lv partition.

While in live CD i did:
lvreduce -L 25G -r /dev/vg_centos/lv_root

Now i want extend lv_var with lvextend -L -r .
But i don't know how to extend to maximum available size.

Before mu lv_root partition was 31G and some megs, but i don't remember how much exactly.

I don't want left free unused space in pvs.

Please help

That's what manpages are for.

It sounds like you might be new to LVM. Hopefully you resized (shrunk) the filesystem before running the lvreduce. Man pages would have mentioned that part too.

Google "tutorial LVM" or "howto LVM" and you should find lots of information and examples. It doesn't serve much use to try to repost all the steps, wisdom, and examples here when it's already readily available elsewhere on the net.

option -r also resize filesystem.

Solved. I get max value from pvs command.

Ahhh, I had forgotten about that option. I remember it now. I also remember in the past that I had chosen not to use it because I prefer to resize the filesystem manually, run a file system check manually to verify integrity, and only then reduce the LV. It is quite possible that the -r option will trigger an automatic file system check between the resize and reduce steps. I didn't know that at the time (and still don't know if it does or doesn't trigger fsck automatically), so I do the steps manually to make sure. That may be overkill on my part. But until you mentioned -r, I had forgotten about that option. Thanks for reminding me about it.

Yes, it does uses fsck during the reduce/extend.