make local data partition a lvm volume

[copymaster]

Hi

my nodes of the cluster have a 3 1TB Disk Raid 5 which makes 2 TB storage on the node.

The storage is named "local" in the webinterface. is it possible to make a LVM-Volume group from that storage?

it seems to be /dev/pve/data but i don't know if that is a "pseudo" udev node or a real one.

I installed the cluster and tested the scenario where the vms are lying on a maped iscsi/LVM storage.
Now i want to test local lvm and backup to a iscsi Lun. I want to test the performance of local installed vm's against those lying on a iscsi/lvm storage.

so the question is:

can i create a lvm group from the /dev/pve/data partition or is it not possible?


my first attempt was simply using the webinterface from the node and select add volumegroup, but this way i get a "You don't have write access" error?

 

[dietmar]

it seems to be /dev/pve/data but i don't know if that is a "pseudo" udev node or a real one.

this is VG 'pve' with LV named 'data'.

can i create a lvm group from the /dev/pve/data partition or is it not possible?

you can create a LV in volume group 'pve' - but usually the VG has no free space (because all space is used by the LV 'data' and LV 'root')

my first attempt was simply using the webinterface from the node and select add volumegroup, but this way i get a "You don't have write access" error?

That is because only master node have write access (you cant manage from a slave node).

 

[copymaster]

well what does this mean for my needs?

i would like to convert the data LV to a lvm group if possible.

can you please give advice how to create a lvm group from the "data" part?

i want to use local vms on this lvm group to make use of the snapshot functionality.

 

[dietmar]

i would like to convert the data LV to a lvm group if possible.

/dev/pve/data is already a logical volume on volume group pve. It is formated with an ext3 filesysten on it and mounted at /var/lib/vz

You can try to shrink the LV (or simply backup the contents, unmount, delete, recreate with smaller size, mount it again, restore old content, ...)