Personally, with a SAN, I just grow the volume/disk instead of adding another disk, which works fine without LVM.  With LVM, it's definitely easier if you want multiple disks to look as one.  However, if you grow a disk, I find it slightly easier if it's just a regular partition (at least for the last partition) to grow that partition then it is to dealwith LVM, but both are workable.

However, just a note...  I wouldn't recommend LVM for removable disks as was originally mentioned on this thread for the backup volume, and not always the same one connected.  Perhaps I am just overly paranoid or too little experience using LVM that way, or maybe more of an issue when it first came out, but that never seemed to work well for me.  Not that it didn't work, just more trouble than it's worth...  and you would need to do a vgexport and vgimport each time you switched the disks in addition to simply mounting and umounting the disk...



----- Original Message -----
> More recently, I've been tasked with caring for systems whose
> requirements are much more subject to change, and LVM has proven it's
> value there. This is especially true in SAN or virtual environments
> where the storage admins might just say "ok, here's another 100gb
> 'disk' for you".
...