存储池、归置组和 CRUSH 配置参考

当你创建存储池并给它设置归置组数量时，如果你没指定 Ceph 就用默认值。我们建议更改某些默认值，特别是存储池的副本数和默认归置组数量，可以在运行 pool 命令的时候设置这些值。你也可以把配置写入 Ceph 配置文件的 [global] 段来覆盖默认值。

[global]

	# By default, Ceph makes 3 replicas of objects. If you want to make four 
	# copies of an object the default value--a primary copy and three replica 
	# copies--reset the default values as shown in 'osd pool default size'.
	# If you want to allow Ceph to write a lesser number of copies in a degraded 
	# state, set 'osd pool default min size' to a number less than the
	# 'osd pool default size' value.

	osd pool default size = 4  # Write an object 4 times.
	osd pool default min size = 1 # Allow writing one copy in a degraded state.

	# Ensure you have a realistic number of placement groups. We recommend
	# approximately 100 per OSD. E.g., total number of OSDs multiplied by 100 
	# divided by the number of replicas (i.e., osd pool default size). So for
	# 10 OSDs and osd pool default size = 4, we'd recommend approximately
	# (100 * 10) / 4 = 250.

	osd pool default pg num = 250
	osd pool default pgp num = 250

mon max pool pg num

mon pg create interval

mon pg stuck threshold

osd pg bits

osd pgp bits

osd crush chooseleaf type

osd pool default crush replicated ruleset

osd pool erasure code stripe width

osd pool default size

osd pool default min size

osd pool default pg num

osd pool default pgp num

osd pool default flags

osd max pgls

osd min pg log entries

osd default data pool replay window