随着云计算业务的快速发展，国内外云计算企业的专利之争也愈发激烈。在云计算这样的技术领域，专利储备往往代表着企业最新的技术实力。华云数据本期“智汇华云”专栏将针对“Ceph的正确玩法之指定SSD为主OSD
chengjiudianshangxiaoliangshenhua douyinguanggaojingzhunyinliu
suizheyunjisuanyewudekuaisufazhan，guoneiwaiyunjisuanqiyedezhuanlizhizhengyeyufajilie。zaiyunjisuanzheiyangdejishulingyu，zhuanlichubeiwangwangdaibiaozheqiyezuixindejishushili。huayunshujubenqi“zhihuihuayun”zhuanlanjiangzhendui“cephdezhengquewanfazhizhidingssdweizhuosd，hddweicongosd”jishu，yudajiagongtongfenxiangyunjisuanlingyudezuixinjishuyujiejuefangan。
gaiwenzhangweibenxiliedediwupianwenzhang，womenjiangzaizhihoujixutuichubenxiliedeqitawenzhang，jingqingguanzhu!
场景一：
dangqianjiqunhuanjingzhonghunyongle ssd yu sata cipan。
场景二：
dangqianjuyouyipidaxiaoyiyangde sata cipan，qizhong osd.0 yijingshiyonglehenduonian，qitaosdcipandoushixincaigou，xingnenghuibi osd.0 gengjiahao。
shiyanshizhongyouliangpisascipan，yipishi7200zhuancipan，yipishi10000zhuancipan。
期望结果：
jiqunzhongcunzaiduozhongxingnengbuyiyangdecipanyuzhuji，weilebaozhengceph jiquntuntuyuxingnengkeyidedaogenghaodeyouhua。baozhenglecipandeshujurongliangyizhideqingkuangxiayouxianshiyongxingnenggenghaodecipanzuochu io chuli。
总结
ceph huirenweimeigecipannengliyiyang，huipingjunmeigecipande io nengli(primary affinity)yucunchukongjiannengli(weight) primary affinity。canshukeyizaibugaibiancipancunchunenglideqingkuangxia, jiangdizai ceph jiqunshiyongguochengzhongduigaiosdderengou primary pg nengli。
congshangtukanchulai， primary osd zaimeici peering shi, douhuibi secondary osd juyougengduode io。
/etc/ceph/ceph.conf
[mon]
mon_osd_allow_primary_affinity = true
zhongqiceph-mon
ceph osd primary-affinity osd.4 0.5
yanzheng： xiugaiquanxianzhiqian：
ceph pg dump | grep active+clean | grep '\[4' | wc -l
48
修改权重之后
ceph pg dump | grep active+clean | grep '\[4' | wc -l
8
