红帽全球峰会4.4.3. 调整 cluster map Size
对于红帽 Ceph 存储版本 2 和更早版本，当集群有数千个 OSD 时，请下载 cluster map 并检查其文件大小。默认情况下，ceph -osd 守护进程缓存 500 以前的 osdmaps。即使使用 deduplication，映射也可能消耗每个守护进程的大量内存。在 Ceph 配置文件中调优缓存大小可能有助于显著减少内存消耗。例如：
对于红帽 Ceph 存储版本 3 及更高版本，ceph-manager 守护进程处理 PG 查询，因此 cluster map 不会影响性能。
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