前言
pool 是ceph一个重要的概念，pool是管理硬件存储设备的，同时可以实现存储的差异化。比如说，有些数据要求可靠性高，那么可以创建一个3副本的pool，有些数据访问对性能要求非常高，可以将其创建在性能比较好的硬件设备上。
数据在集群存储设备的分布，遵循一个pool -> pg ->OSD这样一个定位流程。
本文介绍pool相关的一些指令
命令
列出所有的pool
root@node2:~# ceph osd lspools
0 rbd,1 .ezs3,2 data,3 metadata,4 .rgw.buckets,5 .ezs3.central.log,6 .ezs3.statistic,7 .rgw.root,8 .rgw.control,9 .rgw,10 .rgw.gc,11 .users.uid,12 .users.email,13 .users,14 .users.swift,15 .usage,16 .rgw.buckets.index,
root@node2:~# rados lspools
rbd
.ezs3
data
metadata
.rgw.buckets
.ezs3.central.log
.ezs3.statistic
.rgw.root
.rgw.control
.rgw
.rgw.gc
.users.uid
.users.email
.users
.users.swift
.usage
.rgw.buckets.index
查看pool的副本个数
ceph osd pool get data size
size: 2
对于纠删码，稍微有所不同，因为纠删码是k ＋ m这种类型，因此查看纠删码的k＋m的方法如下：
ceph osd pool get ec-pool-1 size
size: 20
ceph osd pool get ec-pool-1 min_size
min_size: 17
从上面输出可以看出是17+3的纠删码
查看pool上pg_num和pgp_num
ceph osd pool get data pg_num
pg_num: 1024
ceph osd pool get data pgp_num
pgp_num: 1024
修改pg_num和pgp_num
ceph osd pool set pool-1 pg_num 2048
ceph osd pool set pool-1 pgp_num 2048
查看pool的ruleset id
root@node2:~# ceph osd pool get data crush_ruleset
crush_ruleset: 0
查看pool的crush ruleset信息
root@node2:~# ceph osd crush rule dump
[
{ "rule_id": 0,
"rule_name": "data",
"ruleset": 0,
"type": 1,
"min_size": 1,
"max_size": 10,
"steps": [
{ "op": "take",
"item": -1,
"item_name": "default"},
{ "op": "chooseleaf_firstn",
"num": 0,
"type": "host"},
{ "op": "emit"}]},
{ "rule_id": 1,
"rule_name": "metadata",
"ruleset": 1,
"type": 1,
"min_size": 1,
"max_size": 10,
"steps": [
{ "op": "take",
"item": -1,
"item_name": "default"},
{ "op": "chooseleaf_firstn",
"num": 0,
"type": "host"},
{ "op": "emit"}]},
{ "rule_id": 2,
"rule_name": "rbd",
"ruleset": 2,
"type": 1,
"min_size": 1,
"max_size": 10,
"steps": [
{ "op": "take",
"item": -1,
"item_name": "default"},
{ "op": "chooseleaf_firstn",
"num": 0,
"type": "host"},
{ "op": "emit"}]}]
查看pool上的实时I/O信息
root@node-01:~# ceph osd pool stats
pool rbd id 0
nothing is going on
pool data id 2
nothing is going on
pool metadata id 3
client io 2778 B/s wr, 1 op/s
...
pool ec-pool id 15
nothing is going on
pool cache-pool id 16
client io 444 MB/s wr, 446 op/s
获取pool的空间使用情况
root@node2:~# ceph df
GLOBAL:
SIZE AVAIL RAW USED %RAW USED
270G 261G 9388M 3.38
POOLS:
NAME ID USED %USED MAX AVAIL OBJECTS
rbd 0 0 0 130G 0
.ezs3 1 0 0 130G 0
data 2 971M 0.35 130G 223181
metadata 3 44605k 0.02 130G 510136
.rgw.buckets 4 295k 0 130G 1
.ezs3.central.log 5 770k 0 130G 158
.ezs3.statistic 6 2964k 0 130G 52
.rgw.root 7 840 0 130G 3
.rgw.control 8 0 0 130G 8
.rgw 9 349 0 130G 2
.rgw.gc 10 0 0 130G 32
.users.uid 11 835 0 130G 3
.users.email 12 20 0 130G 2
.users 13 20 0 130G 2
.users.swift 14 31 0 130G 3
.usage 15 0 0 130G 1
.rgw.buckets.index 16 0 0 130G 1
root@node2:~# rados df
pool name category KB objects clones degraded unfound rd rd KB wr wr KB
.ezs3 - 0 0 0 0 0 0 0 0 0
.ezs3.central.log - 771 158 0 0 0 0 0 211 1105
.ezs3.statistic - 2965 52 0 0 0 3015628 2721256 1719478 1400229
.rgw - 1 2 0 0 0 0 0 5 2
.rgw.buckets - 296 1 0 0 0 9 6 32 1121
.rgw.buckets.index - 0 1 0 0 0 39 38 21 0
.rgw.control - 0 8 0 0 0 0 0 0 0
.rgw.gc - 0 32 0 0 0 22678 22678 15233 0
.rgw.root - 1 3 0 0 0 339394 203635 5 5
.usage - 0 1 0 0 0 21 21 42 0
.users - 1 2 0 0 0 0 0 2 2
.users.email - 1 2 0 0 0 0 0 2 2
.users.swift - 1 3 0 0 0 0 0 3 3
.users.uid - 1 3 0 0 0 51 44 21 5
data - 995013 223181 0 0 0 8952 127 461125 995026
metadata - 44455 510136 0 0 0 1479663 12983152 3209403 4802054
rbd - 0 0 0 0 0 0 0 0 0
total used 9610440 733585
total avail 274364640
total space 284073384
其他
纠删码pool会有更多很有意思的控制参数， 可以通过 ceph osd pool get [pool_name] 来试探出支持的参数。
这些参数如下所示，至于具体的含义和作用，内容比较多，就不再此处列出。
root@node2:~# ceph osd pool get data
Invalid command: missing required parameter var(size|min_size|crash_replay_interval|pg_num|pgp_num|crush_ruleset|hit_set_type|hit_set_period|hit_set_count|hit_set_fpp|auid|target_max_objects|target_max_bytes|cache_target_dirty_ratio|cache_target_full_ratio|cache_min_flush_age|cache_min_evict_age|erasure_code_profile|min_read_recency_for_promote)
osd pool get <poolname> size|min_size|crash_replay_interval|pg_num|pgp_num|crush_ruleset|hit_set_type|hit_set_period|hit_set_count|hit_set_fpp|auid|target_max_objects|target_max_bytes|cache_target_dirty_ratio|cache_target_full_ratio|cache_min_flush_age|cache_min_evict_age|erasure_code_profile|min_read_recency_for_promote : get pool parameter <var>
Error EINVAL: invalid command