ceph按hdd和ssd创建不同ceph pool

ceph区分hdd和ssd硬盘创建不同的ceph pool

原文：[ceph区分hdd和ssd存储](https://www.cnblogs.com/x602/p/16375896.html "ceph区分hdd和ssd存储")

也适用于pve8的ceph环境

## 1.集群中添加osd
确定磁盘已经加进集群，CLASS 类型ceph 会自动识别出来
最少两种磁盘类型3块，不然创建pool默认副本为3，磁盘数少于3，会写入pool异常，也可以手动修改pool副本数为1
```
[root@node3 ~]# ceph osd tree
ID CLASS WEIGHT  TYPE NAME      STATUS REWEIGHT PRI-AFF 
-1       0.05878 root default                           
-3       0.01959     host node1                         
 3   hdd 0.00980         osd.3      up  1.00000 1.00000 
 0   ssd 0.00980         osd.0      up  1.00000 1.00000 
-5       0.01959     host node2                         
 4   hdd 0.00980         osd.4      up  1.00000 1.00000 
 1   ssd 0.00980         osd.1      up  1.00000 1.00000 
-7       0.01959     host node3                         
 5   hdd 0.00980         osd.5      up  1.00000 1.00000 
 2   ssd 0.00980         osd.2      up  1.00000 1.00000 
```

## 2.创建rule
```
[root@node3 ~]# ceph osd crush rule create-replicated rule-ssd default  host ssd 
[root@node3 ~]# ceph osd crush rule create-replicated rule-hdd default  host hdd 
```

上面2行命令的效果，相当于在配置文件中增加：
```
rule rule-ssd {
	id 3
	type replicated
	step take default class ssd
	step chooseleaf firstn 0 type host
	step emit
}
rule rule-hdd {
	id 4
	type replicated
	step take default class hdd
	step chooseleaf firstn 0 type host
	step emit
}
```
## 3.创建pool
```
[root@node3 ~]# ceph osd pool create ssdpool 64 64 rule-ssd
正常会提示创建成功： pool 'ssdpool' created
```

## 4.创建对象测试ssdpool
```
[root@node3 ~]# rados -p ssdpool ls
[root@node3 ~]# echo "hahah" >test.txt
[root@node3 ~]# rados -p ssdpool put test test.txt 
[root@node3 ~]# rados -p ssdpool ls
test
```

查看该对象的osd组：
```
[root@node3 ~]# ceph osd map ssdpool test
osdmap e46 pool 'ssdpool' (1) object 'test' -> pg 1.40e8aab5 (1.35) -> up ([1,2,0], p1) acting ([1,2,0], p1)
```

可以看到该对象的osd组使用的都是ssd磁盘，至此验证成功。可以看出crush class相当于一个辨别磁盘类型的标签。

## 5.修改以前创建好的pool规则
`ceph osd pool set oldpool crush_rule rule-hdd`

## 补充
```
修改CrushRule：
ceph osd pool set [存储池名] crush_rule [CrushRule规则名]

修改默认备份数：
ceph osd pool set [存储池名] size [份数]

修改最小备份数（低于这个就停止写入）：
ceph osd pool set [存储池名] min_size [份数]
```

ceph-创建使用rule-ssd规则的存储池：https://blog.csdn.net/wangyiyan315/article/details/124022377
官方文档：https://docs.ceph.com/en/latest/rados/operations/crush-map/