growing a live LVM volume

I have an LVM volume, with xfs on it, that is almost full:

$ df /scratch -h
Filesystem                Size  Used Avail Use% Mounted on
/dev/mapper/vg-scratch    180G  175G  5.4G  98% /scratch

$ sudo lvdisplay /dev/mapper/vg-scratch
...
  LV Size                180.00 GB
...

But I have some more space in the physical volume. Let’s grow the logical volume.

First, let’s grow the volume by 20G…

$ sudo lvresize -L +20G /dev/mapper/vg-scratch
  Extending logical volume scratch to 200.00 GB
  Logical volume scratch successfully resized

$ sudo lvdisplay /dev/mapper/vg-scratch
...
  LV Size                200.00 GB
...

Next, let’s tell the XFS file system to fill in the space…

$ sudo xfs_growfs /scratch
...
data blocks changed from 47185920 to 52428800

$ df /scratch -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg-scratch
                      200G  175G   26G  88% /scratch