kernel-5.14.0-597.el9    BUILT: Fri Jul  4 07:37:15 PM CEST 2025
lvm2-2.03.32-2.el9    BUILT: Tue Jun  3 01:49:02 PM CEST 2025
lvm2-libs-2.03.32-2.el9    BUILT: Tue Jun  3 01:49:02 PM CEST 2025
kmod-kvdo-8.2.6.3-169.el9    BUILT: Tue Jul  8 07:23:43 PM CEST 2025
 
 
# NORMAL SIZED volume to convert to thinpool with backing vdo volume for pool
[root@virt-484 ~]# lvcreate --yes --type linear -n convert_pool  -L 12G thinpool_sanity
  Logical volume "convert_pool" created.
 
[root@virt-484 ~]# lvconvert --yes --type thin-pool --pooldatavdo y thinpool_sanity/convert_pool
  Thin pool volume with chunk size 64.00 KiB can address at most <15.88 TiB of data.
  WARNING: Converting thinpool_sanity/convert_pool to thin pool's data volume with metadata wiping.
  THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.)
    The VDO volume can address 8 GB in 4 data slabs, each 2 GB.
    It can grow to address at most 16 TB of physical storage in 8192 slabs.
    If a larger maximum size might be needed, use bigger slabs.
  Logical volume "convert_pool" created.
  Converted thinpool_sanity/convert_pool to thin pool.
 
[root@virt-484 ~]# lvs -a -o +devices
  LV                          VG              Attr       LSize  Pool                Origin Data%  Meta%  Move Log Cpy%Sync Convert Devices                     
  convert_pool                thinpool_sanity twi-a-tz-- 12.00g                            0.00   10.68                            convert_pool_tdata(0)       
  [convert_pool_tdata]        thinpool_sanity vwi-aov--- 12.00g convert_pool_vpool0        0.00                                    convert_pool_vpool0(0)      
  [convert_pool_tmeta]        thinpool_sanity ewi-ao---- 12.00m                                                                    /dev/sda(3072)              
  convert_pool_vpool0         thinpool_sanity dwi------- 12.00g                            33.38                                   convert_pool_vpool0_vdata(0)
  [convert_pool_vpool0_vdata] thinpool_sanity Dwi-ao---- 12.00g                                                                    /dev/sda(0)                 
  [lvol0_pmspare]             thinpool_sanity ewi------- 12.00m                                                                    /dev/sda(3075)              
 
 
 
 
# UNDER SIZED volume to convert to thinpool with backing vdo volume for pool
[root@virt-484 ~]# lvcreate --yes --type linear -n convert_pool  -L 12M thinpool_sanity
  Logical volume "convert_pool" created.
[root@virt-484 ~]# lvs -a -o +devices
  LV           VG              Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert Devices       
  convert_pool thinpool_sanity -wi-a----- 12.00m                                                     /dev/sda(0)   
 
[root@virt-484 ~]# lvconvert --yes --type thin-pool --pooldatavdo y thinpool_sanity/convert_pool
  Thin pool volume with chunk size 64.00 KiB can address at most <15.88 TiB of data.
  WARNING: Converting thinpool_sanity/convert_pool to thin pool's data volume with metadata wiping.
  THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.)
Minimum required size for VDO volume: 5063921664 bytes
vdoformat: formatVDO failed on '/dev/thinpool_sanity/convert_pool_vpool0': VDO Status: Out of space
  Command /usr/bin/vdoformat failed.
  Cannot format VDO pool volume thinpool_sanity/convert_pool_vpool0.

# Manual cleanup is now required  
[root@virt-484 ~]# lvs -a -o +devices
  LV                  VG              Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert Devices       
  convert_pool_vpool0 thinpool_sanity -wi-a----- 12.00m                                                     /dev/sda(0)   
  [lvol0_pmspare]     thinpool_sanity ewi-------  4.00m                                                     /dev/sda(4)   
  pool_metadata0      thinpool_sanity -wi-a-----  4.00m                                                     /dev/sda(3)