My Fedora 17 (x64 - running on VMware 8) root filesystem is running out of space (this was an install using the default layout as suggested by the Fedora installer):
<pre>
# df -h
Filesystem Size Used Avail Use% Mounted on
rootfs 18G 17G 937M 95% /
devtmpfs 1.5G 0 1.5G 0% /dev
tmpfs 1.5G 224K 1.5G 1% /dev/shm
tmpfs 1.5G 51M 1.5G 4% /run
/dev/mapper/vg_bloss-lv_root 18G 17G 937M 95% /
tmpfs 1.5G 51M 1.5G 4% /run
tmpfs 1.5G 0 1.5G 0% /sys/fs/cgroup
tmpfs 1.5G 0 1.5G 0% /media
/dev/sda2 485M 85M 376M 19% /boot
</pre>

The bulk of the space is taken up by the `/usr` directory. I have added a 40GB disk to the virtual machine (`/dev/sdb`) and wish to move `/usr` to its own logical volume.

LVM is a bit new to me but I think I've worked out the steps to add this disk using LVM:
<pre>
fdisk /dev/sdb 
# (create a new 0x8e LVM partition type using all of the disk)

pvcreate /dev/sdb1
vgextend vg_bloss /dev/sdb1
lvcreate -l +100%FREE -n lv_usr vg_bloss /dev/sdb1
mkfs -t ext4 /dev/vg_bloss/lv_usr
# mount fs
mkdir /mnt/usr
mount -t ext4 /dev/vg_bloss/lv_usr /mnt/usr
</pre>

I was then going to use the following steps to move `/usr` onto this new filesystem:
<pre>
cp -aR /usr/* /mnt/usr
umount /mnt/usr
mv /usr /usr_old
mkdir /usr
mount -t ext4 /dev/vg_bloss/lv_usr /usr
# and add relevant entry in fstab
</pre>

Does this look sane?