add partition prefix variable support for deployments with ceph-volume

Related-Prod: PROD-34576
Change-Id: I2ca6c55013ec5cb9fde25402d9d460bc03f30b41
diff --git a/ceph/osd/setup/lvm.sls b/ceph/osd/setup/lvm.sls
index eb6e72e..915caed 100644
--- a/ceph/osd/setup/lvm.sls
+++ b/ceph/osd/setup/lvm.sls
@@ -38,6 +38,7 @@
 
 {% set db_partition = disk.get('db_partition') %}
 {% set wal_partition = disk.get('wal_partition') %}
+{% set block_partition_prefix = disk.get('block_partition_prefix', '') %}
 
 {%- endif %}
 
@@ -50,10 +51,10 @@
 {%- endif %}
 {%- do cmd.append('--bluestore') %}
 {%- if disk.block_db is defined %}
-  {%- do cmd.append('--block.db ' + disk.block_db + db_partition | string) %}
+  {%- do cmd.append('--block.db ' + disk.block_db + block_partition_prefix + db_partition | string) %}
 {%- endif %}
 {%- if disk.block_wal is defined %}
-  {%- do cmd.append('--block.wal ' + disk.block_wal + wal_partition | string ) %}
+  {%- do cmd.append('--block.wal ' + disk.block_wal + block_partition_prefix + wal_partition | string ) %}
 {%- endif %}
 {%- do cmd.append('--data ') %}
 {%- do cmd.append(dev) %}