Hello, I have a physical node and the system uses lvm partitions. With the service already running above, is it possible for me to deploy cinder-volume that uses the lvm backend without affecting the existing service? The physical disk space is basically allocated to the /dev/sda4 physical volume, and the pv wad added to the `uniontechos` volume group. All the space of `uniontechos` vg is allocated to the system logical volume (/dev/uniontechos/root), there is 5T space (a lot of free space). I want to try to reduce the system logical volume——/dev/uniontechos/root, and let cinder-volume use the uniontechos volume group at the same time , I don't know if it is feasible. Could I get some advices? Thank for any help! ```shell # pvdisplay ... --- Physical volume --- PV Name /dev/sda4 VG Name uniontechos PV Size <5.43 TiB / not usable 2.00 MiB Allocatable yes (but full) PE Size 4.00 MiB Total PE 1422313 Free PE 0 Allocated PE 1422313 PV UUID 8LF270-LYD1-kuP1-iWZb-BZEQ-LdA8-UwEa58 # lvdisplay --- Logical volume --- LV Path /dev/uniontechos/root LV Name root VG Name uniontechos LV UUID cEypcY-xcbC-JFoO-d3MS-uMPU-ntQa-WEeE1c LV Write Access read/write LV Creation host, time compute2, 2022-04-28 15:21:27 +0800 LV Status available # open 1 LV Size 5.42 TiB Current LE 1421289 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:0 ``` Best wishes, Han