Ceph CRUSHMap to replicate over datacenters

crushmap.txt

# begin crush map
tunable choose_local_tries 0
tunable choose_local_fallback_tries 0
tunable choose_total_tries 50
tunable chooseleaf_descend_once 1
tunable chooseleaf_vary_r 1
tunable chooseleaf_stable 1
tunable straw_calc_version 1
tunable allowed_bucket_algs 54

# devices
device 0 osd.0 class ssd
device 1 osd.1 class ssd
device 2 osd.2 class ssd
device 3 osd.3 class ssd
device 4 osd.4 class ssd
device 5 osd.5 class ssd

# types
type 0 osd
type 1 host
type 2 chassis
type 3 rack
type 4 row
type 5 pdu
type 6 pod
type 7 room
type 8 datacenter
type 9 region
type 10 root

# buckets
host alpha {
	id -3		# do not change unnecessarily
	id -4 class ssd		# do not change unnecessarily
	# weight 0.010
	alg straw2
	hash 0	# rjenkins1
	item osd.0 weight 0.010
}
host bravo {
	id -5		# do not change unnecessarily
	id -6 class ssd		# do not change unnecessarily
	# weight 0.010
	alg straw2
	hash 0	# rjenkins1
	item osd.1 weight 0.010
}
host charlie {
	id -7		# do not change unnecessarily
	id -8 class ssd		# do not change unnecessarily
	# weight 0.010
	alg straw2
	hash 0	# rjenkins1
	item osd.2 weight 0.010
}
datacenter dc1 {
	id -15		# do not change unnecessarily
	id -16 class ssd		# do not change unnecessarily
	# weight 0.029
	alg straw2
	hash 0	# rjenkins1
	item alpha weight 0.010
	item bravo weight 0.010
	item charlie weight 0.010
}
host delta {
	id -9		# do not change unnecessarily
	id -10 class ssd		# do not change unnecessarily
	# weight 0.010
	alg straw2
	hash 0	# rjenkins1
	item osd.3 weight 0.010
}
host echo {
	id -11		# do not change unnecessarily
	id -12 class ssd		# do not change unnecessarily
	# weight 0.010
	alg straw2
	hash 0	# rjenkins1
	item osd.4 weight 0.010
}
host foxtrot {
	id -13		# do not change unnecessarily
	id -14 class ssd		# do not change unnecessarily
	# weight 0.010
	alg straw2
	hash 0	# rjenkins1
	item osd.5 weight 0.010
}
datacenter dc2 {
	id -17		# do not change unnecessarily
	id -18 class ssd		# do not change unnecessarily
	# weight 0.029
	alg straw2
	hash 0	# rjenkins1
	item delta weight 0.010
	item echo weight 0.010
	item foxtrot weight 0.010
}
root default {
	id -1		# do not change unnecessarily
	id -2 class ssd		# do not change unnecessarily
	# weight 0.058
	alg straw2
	hash 0	# rjenkins1
	item dc1 weight 0.029
	item dc2 weight 0.029
}

# rules
# Works best with 4 replicas
# Two different hosts will be selected in each datacenter
# This allows for a DC to fail
rule replicated_rule {
	id 0
	type replicated
	min_size 1
	max_size 4
	step take default
	step choose firstn 2 type datacenter
	step chooseleaf firstn 2 type host
	step emit
}