[ceph-users] Ceph WAL/DB disks - do they really only use 3GB, or 30Gb, or 300GB

Hi, I'm using Intel Optane disks to provide WAL/DB capacity for my Ceph cluster (which is part of Proxmox - for VM hosting). I've read that WAL/DB partitions only use either 3GB, or 30GB, or 300GB - due to the way that RocksDB works. Is this true? My current partition for WAL/DB is 145 GB - does this mean that 115Gb of that will be permanently wasted? Is this behaviour documented somewhere, or is there some background, so I can understand a bit more about how it works? Thanks, Victor