On Mon, 2011-08-15 at 15:54 -0400, James B. Byrne wrote: > I am performing some configuration testing on a kvm host. When > installing a guest operating system is it advisable to place each > instance in a separate lv or better to accept the default and store > them on the root file system? I think you are asking LV based or file based guest storage. I vote for LV on the host. > Respecting lvm, does one configure lvs in a virtual server to take > space from the main vg or does one allocate lv space from inside > that allocated to the virtual instance? Is it even considered > advisable to use lvs with virtual guests? > ... It seems that you are asking whether to use (1) multiple host LV's to keep different partitions on different virtual disks, (2) a single host LV with nested LVM or (3) a single host LV with traditional partitioning... I use Xen, but if we treat this as a philosophical discussion, that probably doesn't matter. I like option 1 (multiple host LVs) for the flexibility it gives, but I don't like the large number of LVs on the host. I don't like option 2 (nested LVM) due to the difficulties of resizing guest PV. Option 3 (single host LV, raw guest partitions) keeps the number of host LVs lower, but only the last guest partition is easily resized. If you can accept the number of LVs or you need to resize your partitions frequently, I'd recommend option 1. I have gravitated to option 3 because I find I don't need to resize my guest virtual disks very often. MS Windows uses a single partition, so those VMs are simple. On my Linux VMs, I normally only need to resize either the var partition or the home partition depending on the machine's function, but not both, so I put that partition last. I recommend against using LVM within a VM.