[ceph] add tool to locate the block device

ceph/find-osd-device.sh

@@ -0,0 +1,43 @@
+#!/bin/sh
+# Locate which block device corresponds to the OSD
+# Nico Schottelius, 2023-06-10
+
+
+if [ $# -ne 1 ]; then
+    echo $0 osdnum
+    echo f.i. $0 99
+    exit 1
+fi
+
+osdid=$1; shift
+
+osd_path=/var/lib/ceph/osd/ceph-${osdid}
+
+mountpath=$(mount | grep "on ${osd_path} ")
+
+if [ -z ${mountpath} ]; then
+    echo "Nothing mounted on ${osd_path}, are you on the right host?"
+    exit 1
+fi
+
+blockdev=$(readlink -f ${mountpath}/block)
+
+# Is directly referring to sdX? print and exit
+if echo $blockdev | grep -q ^/dev/sd; then
+    echo $blockdev
+    exit 0
+fi
+
+# try the non-recursive variant, resulting in finding pv/vg
+blockdev=$(readlink ${mountpath}/block)
+lvm_vg=$(echo $blockdev | awk -F/ '{ print $3 }')
+
+pv_name=$(pvdisplay | grep -B1 $lvm_vg | awk '/PV Name/ { print $3 }')
+
+if [ "$pv_name" ]; then
+    echo $pv_name
+    exit 0
+fi
+
+echo "Cannot determine block device for osd.${osdid}" >&2
+exit 1