I'm setting up a Xen virtual machine server and I'm wondering which of these three options of disk setup is recommended. I'll be using a Linux host with Linux guests.
As I can see it I can do any of the following:
- Give the domU's a partition of the physical disk, then setup an LVM in the domU inside the partition.
- Give the domU's a Logical Volume to use as a virtual disk, then (a) setup partitions or (b) setup LVM inside.
- Give the domU's multiple Logical Volumes that are used directly.
Number 1 has the advantage that you get LVM in the domU, but you lose the flexibility of LVM in the dom0. However, 2a & 3 give the flexibility of LVM to dom0, but take it away from the domUs.
The most flexible situation appears to be to give the domUs a Logical Volume, as their entire disk, then to create a LVM setup in the LV (option 2b). Would the LVM in LVM cause problems with performance, or something else that I'm not anticipating?
What setup do you use, and why?
Best Answer
"easiest to manage" is very relative - you just as well use file-based disk images and it would be ... simple - at least for a few guests.
Still, i would say option 2 is fine, though using LVM in the domU is completely optional. Of course, if you plan on expanding the LVs for the domUs later, having them use LVM will make things easier.
That i know of, there are no performance issues with having LVM in the domUs (it's not LVM inside LVM, its LVm inside Xen...)