#!/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

osd_id=$1; shift

osd_path=/var/lib/ceph/osd/ceph-${osd_id}

if ! mount | grep -q " on ${osd_path} "; then
    echo "Nothing mounted on ${osd_path}, are you on the right host?"
    exit 1
fi

blockdev=$(readlink -f ${osd_path}/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 ${osd_path}/block)
lvm_vg=$(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