On Mon, December 19, 2011 18:04, Jeff Boyce wrote:
Greetings -
I am hoping someone can confirm for me the steps that I am using to add an LV to an existing Guest in KVM, and what I am seeing as I do some of these steps.
I think that you will find it easier to create guest storage volumes entirely from within virt-manager or virsh and not try and manipulate them directly on the host. I have done so in the past but it adds a layer of complexity to the process that yields no discernible benefits.
Here is what I have hit upon in my own explorations of kvm:
1. Create a virtual storage pool and add it to the host. I use an lv on the host.
2. Create initial guest instance and allocate a new volume from the storage pool using virt-manager -> details -> storage window through the guest storage browser. Name the new storage volume to something related to the vm guest name.
3. Complete creating the vm guest.
4. To add additional storage to an existing vm guest first open the guest's -> details -> hardware menu tab and then select Add Storage.
5. In the guest hardware storage window select VirtIO type, raw format, and press the browse button.
6. In the host storage window select the storage pool to allocate storage from.
7. Select add a New Volume.
8. Assign a storage volume name (some variant of the base storage volume such that all volumes assigned to a single guest appear together in the host storage volume window works best for me) and set the new volume size. Refresh the host storage display, select the new volume name, and return to the guest storage window.
9. Push the Finish button. Restart the guest.
10. Now open the guest console, find the newly added device (fdisk -l ), say /dev/vdb for example, and partition it using fdisk or parted. I always make one partition for the entire device. Refresh the devices using parted.
11. Now add the newly partitioned device to the guest's own vg using the normal lvm tools.
12. Now create new or expand existing lvs on the guest using lvm.
The only trouble I had, well towards the end the only trouble that I had left, was discovering that a VirtIO storage volume is not automatically partitioned when created. Until it had a partition I could not add it to the guest's vg even though I could see the device.
HTH.