Hi,

I've been reading about LVM and wondering if it might be worth using it on my home machine to simplify partition management.

However, if I've got 2 Linux distros installed, would I be right in thinking that VGs and LVs created by one installation won't be visible to the other one? So I couldn't, say, use LVM to reduce the size of / for one installation and move the free space to the / of the other?

Nope, it can be done. It's just a matter of ensuring the correct lvs are mounted in each case.
You'll probably still want an individual /boot partition for each distro to keep things clean. 100M each should be more than enough. It's not strictly necessary, but its tidy.

sda1 100M linux partition mounted as /boot for distro1
sda2 100M linux partition mounted as /boot for distro2
sda3 100M linux partition mounted as /boot for distro3
sda4 rest of disk in type 8e LVM partition used as PV.

Within the vg you would then create
/dev/sharedvg/lvroot_d1
/dev/sharedvg/lvroot_d2
/dev/sharedvg/lvroot_d3
/dev/sharedvg/lvswap00 (can be shared)


Gaz.

Ok, thanks. So for example, could I partition a drive as per your suggestion, use a live CD to create LVs on the large partition, and the standard graphical installers for various distros (ubuntu, fedora, suse, slack, ...) will recognise the lvm stuff and allow me to install / to an LV? Or would the installation be a bit more involved?

I guess it would be distro specific. I'm a slackware user and Slackware's installer is certainly flexible enough to allow something like this (you do all the partitioning from the command line anyway). I've also done an Ubuntu on lvm install before, but it requires a little messing about, you need to apt-get the lvm support as it isn't on the live cd, and setup the lvm stuff from the command line prior to running the installer, stuff like that. There's a number of guides to doing Ubuntu LVM out there, a quick google should find one.

Whether it's worth all the trouble is a different question however. By taking this sort of approach you're stepping outside 'the norm' with these distributions and that might lead to a few maintenance headaches in future. (most likely to bite you with the more 'automated' distributions).