ceph 之osd 分类（class）

1. ceph不能自动识别磁盘类型
2. 设置osd分类前osd需要是未分类的，即：修改osd分类的做法是，先移除原有的分类，在添加新的分类：
   
   ceph osd crush rm-device-class ssd osd.5 osd.6 osd.7 ceph osd crush set-device-class ssd osd.5 osd.6 osd.7

   1 2	ceph osd crush rm-device-class ssd osd.5 osd.6 osd.7 ceph osd crush set-device-class ssd osd.5 osd.6 osd.7

   
    
3. 操作osd分类使用的不是ceph osd crush class *
4. 根据磁盘分类查看osd：
   
   # ceph osd crush class ls [ "hdd", "ssd" ] # ceph osd crush class ls-osd hdd 0 1 2 3 4 # ceph osd crush class ls-osd ssd 5 6 7

   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

   # ceph osd crush class ls [     "hdd",     "ssd" ] # ceph osd crush class ls-osd hdd 0 1 2 3 4 # ceph osd crush class ls-osd ssd 5 6 7

   
    
5. 然后参考ceph osd crush rule 来创建自己的规则，如只存放在hdd上，或只存放在ssd上的规则，然后对pool设置响应的规则
6. class 不需要预先创建：
   
   [root@ceph-test-1 mnt]# ceph osd crush rm-device-class osd.1 done removing class of osd(s): 1 [root@ceph-test-1 mnt]# ceph osd crush set-device-class ssd osd.1 set osd(s) 1 to class 'ssd' [root@ceph-test-1 mnt]# ceph osd crush class ls-osd ssd 1 [root@ceph-test-1 mnt]# ceph osd crush class ls [ "hdd", "ssd" ]

   1 2 3 4 5 6 7 8 9 10 11

   [root@ceph-test-1 mnt]# ceph osd crush rm-device-class osd.1 done removing class of osd(s): 1 [root@ceph-test-1 mnt]# ceph osd crush set-device-class ssd osd.1 set osd(s) 1 to class 'ssd' [root@ceph-test-1 mnt]# ceph osd crush class ls-osd ssd 1 [root@ceph-test-1 mnt]# ceph osd crush class ls [     "hdd",     "ssd" ]

   
   没有提供一个方法add class ssd， 也没看到一个方法可以del class ssd

参考： http://docs.ceph.com/docs/master/rados/operations/crush-map/