[linux-lvm] How to automate lvextend?

[Andreas Trawoeger wgkk at]

Hi!

Is there a sane or somewhat standard
way to automate lvextend?

I'm running LVM2 on my laptop and I'm
pretty happy with it (lvm is great if you run 3 different distros and disk
space is tight).

Main problem I have is that I have to
be quite restrictive with space allocation (it't difficult to add disk
space to a laptop) and regularily run into full filesystems. Which is annoying
and you end up having problems like not beeing able to log into KDE, because
your home directory is full.

But is is extremly annoying when you
would like to use snapshots. Snaphshots are a great way to keep older versions
of your file, but they are basically useless if they either have to be
unnecessarily  large (you won't have the disc space to do it), or
get invalidated pretty often (which isn't what you want to happen to your
backup).

In theory it shouldn't be too difficult
to have a script that regularily checks the fill rate of your  filesystems
and snapshots and do an lvextend if necessary. But for snapshots it would
be great if lvm could do the lvextend by it self and it shouldn't be too
difficult to teach ext3 to do the same with a normal lv.


cu andreas