I've been using this on my home file server for a couple of years now. I just added a couple of multi-GB SATA drives and added them to my "data" VG/LV to make room for all the new DVDs I got for Christmas. :D
That is all.
Yeah, it is real nice and very flexible when needing to add or remove drives, just don't lvm your root partition or you will shoot yourself in the foot.....not that I would know anything about that :)
You can do it but you do have to tread lightly otherwise you will hose your system. You either need to make a /boot that grub can deal with or make a boot disk. Eli here did that for a while, but it became a hasle to deal with in the long run.
We do use LVM at the office quite a bit for our backups since those grow over time.
Well, I have most of my boxes configured with a lvmed root partition and they work just fine. But.....the problem is that not all the tools are available for lvm version 2 to help you easily accomplish this when moving from a 2.4 kernel to a 2.6 kernel. It is possible to create your own initrd script or use ones available through a google search, but that does not insure that it will still work, especially since the device filesystem will come into play, udev I believe. And that is were the majority of the problems can crop up.....so my recommendation after dealing with these pains is don't under any circumstances create a root lvmed partition, unless you have a lot of free time and desire to pull hair out.