Logical Volumes are great you can add disk space without unmounting disk. With ext3 you can expand that space without a downtime. It’s easy.
Assume you add a new disk called /dev/sdg and you partition it into a single partition to keep the blocked lined up with your storage system. Now you have /dev/sdg1
Make it into pv’s
pvcreate /dev/sdg1
Now add it to your current logical volume called storage with the following command
vgextend storage /dev/sdg1
Use vgdisplay to show how many pv’s are used and now many are free… using the next command we need to add them together..
lvextend -l number_of_pvs /dev/storage/storage
Now you need to expand the ext3 which can take some time:
resize2fs /dev/storage/storage
And wait …