Ceph reweight OSD slowly

ceph-reweight-slowly

#!/bin/bash

# Usage:
# ceph-reweight-slowly <OSD-ID> <IN or OUT>
# 
# OUT will reweight osd from 1 to 0 in 0.1 decrements.
# E.g. when removing osd 1 from cluster: `ceph-reweight-slowly 1 out`
# IN  will reweight osd from 0 to 1 in 0.1 increments.
# E.g. when adding osd 5 to cluster: `ceph-reweight-slowly 5 in`
#
# This has minimal impact on cluster performance.
# Definitely lower than when reweighting at once

set -e

OSD=$1
DIRECTION=$2

if [ -z "$OSD" ]; then
	echo "Please specify osd number"
	exit 1
fi

if [ -z "$DIRECTION" ]; then
	echo "Please specify direction (in or out)"
	exit 1
fi

if [[ $DIRECTION == "out" ]]
then
    for i in 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0
    do
	echo "Reweighting OSD $OSD to $i and waiting"
	ceph osd reweight $1 $i
	sleep 30
	while [ $(ceph -s | grep backfil -c) -gt 0 ]; do echo -n .;sleep 30; done
    done
    echo "OSD reweighted to 0"
elif [[ $DIRECTION == "in" ]]
then
    for i in 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
    do
	echo "Reweighting OSD $OSD to $i and waiting"
	ceph osd reweight $1 $i
	sleep 30
	while [ $(ceph -s | grep backfil -c) -gt 0 ]; do echo -n .;sleep 30; done
    done
    echo "OSD reweighted to 1"
else
    echo "Direction must be in or out"
    exit 1;
fi