How can I find out if I can allocate more space to LVM?
 

I am trying to figure out the procedure for figuring out if there is space left on a disk to extend an lvm... either by growing the logical volume to a physical volume that has not been totally allocated or by determining if there is any disk left to add to the pv and then the lv... how do I determine this?

well fdisk, parted etc will show you unallocated partition space, and tools like pvdisplay will show you space within the lvm pv's you already have. you can also then compare the lv's themselves to the size of the filesystems they contain, as there can in principle be wasted space in there, albeit it very unlikely.

To just find out if there is available space, the easiest way is as described by acid*, though I would say cfdisk is the easiest visually.

Main disk /dev/sda
# cfdisk /dev/sda

cfdisk is interesting but it does not seem to be on our servers - thanks for he help though - both you guys!

fdisk doesn't show unpartitioned space, although you can infer it. parted "print" shows the (imbedded) free space nicely. Can be scripted/saved, so it perhaps more useful than cfdisk in cases like this.