Appendix B. Ceph network configuration options These are the common network configuration options for Ceph. public_network Description The IP address and netmask of the public (front-side) network (for example, 192.168.0.0/24 ). Set in [global] . You can specify comma-delimited subnets. Type <ip-address>/<netmask> [, <ip-address>/<netmask>] Required No Default N/A public_addr Description The IP address for the public (front-side) network. Set for each daemon. Type IP Address Required No Default N/A cluster_network Description The IP address and netmask of the cluster network (for example, 10.0.0.0/24 ). Set in [global] . You can specify comma-delimited subnets. Type <ip-address>/<netmask> [, <ip-address>/<netmask>] Required No Default N/A cluster_addr Description The IP address for the cluster network. Set for each daemon. Type Address Required No Default N/A ms_type Description The messenger type for the network transport layer. Red Hat supports the simple and the async messenger type using posix semantics. Type String. Required No. Default async+posix ms_public_type Description The messenger type for the network transport layer of the public network. It operates identically to ms_type , but is applicable only to the public or front-side network. This setting enables Ceph to use a different messenger type for the public or front-side and cluster or back-side networks. Type String. Required No. Default None. ms_cluster_type Description The messenger type for the network transport layer of the cluster network. It operates identically to ms_type , but is applicable only to the cluster or back-side network. This setting enables Ceph to use a different messenger type for the public or front-side and cluster or back-side networks. Type String. Required No. Default None. Host options You must declare at least one Ceph Monitor in the Ceph configuration file, with a mon addr setting under each declared monitor. Ceph expects a host setting under each declared monitor, metadata server and OSD in the Ceph configuration file. Important Do not use localhost . Use the short name of the node, not the fully-qualified domain name (FQDN). Do not specify any value for host when using a third party deployment system that retrieves the node name for you. mon_addr Description A list of <hostname>:<port> entries that clients can use to connect to a Ceph monitor. If not set, Ceph searches [mon.*] sections. Type String Required No Default N/A host Description The host name. Use this setting for specific daemon instances (for example, [osd.0] ). Type String Required Yes, for daemon instances. Default localhost TCP options Ceph disables TCP buffering by default. ms_tcp_nodelay Description Ceph enables ms_tcp_nodelay so that each request is sent immediately (no buffering). Disabling Nagle's algorithm increases network traffic, which can introduce congestion. If you experience large numbers of small packets, you may try disabling ms_tcp_nodelay , but be aware that disabling it will generally increase latency. Type Boolean Required No Default true ms_tcp_rcvbuf Description The size of the socket buffer on the receiving end of a network connection. Disabled by default. Type 32-bit Integer Required No Default 0 Bind options The bind options configure the default port ranges for the Ceph OSD daemons. The default range is 6800:7100 . You can also enable Ceph daemons to bind to IPv6 addresses. Important Verify that the firewall configuration allows you to use the configured port range. ms_bind_port_min Description The minimum port number to which an OSD daemon will bind. Type 32-bit Integer Default 6800 Required No ms_bind_ipv6 Description Enables Ceph daemons to bind to IPv6 addresses. Type Boolean Default false Required No Asynchronous messenger options These Ceph messenger options configure the behavior of AsyncMessenger . ms_async_op_threads Description Initial number of worker threads used by each AsyncMessenger instance. This configuration setting SHOULD equal the number of replicas or erasure code chunks, but it may be set lower if the CPU core count is low or the number of OSDs on a single server is high. Type 64-bit Unsigned Integer Required No Default 3 Connection mode configuration options For most connections, there are options that control the modes that are used for encryption and compression. ms_cluster_mode Description Connection mode used for intra-cluster communication between Ceph daemons. If multiple modes are listed, the modes listed first are preferred. Type String Default crc secure ms_service_mode Description A list of permitted modes for clients to use when connecting to the storage cluster. Type String Default crc secure ms_client_mode Description A list of connection modes, in order of preference, for clients to use when interacting with a Ceph cluster. Type String Default crc secure ms_mon_cluster_mode Description The connection mode to use between Ceph monitors. Type String Default secure crc ms_mon_service_mode Description A list of permitted modes for clients or other Ceph daemons to use when connecting to monitors. Type String Default secure crc ms_mon_client_mode Description A list of connection modes, in order of preference, for clients or non-monitor daemons to use when connecting to Ceph monitors. Type String Default secure crc Compression mode configuration options With the messenger v2 protocol, you can use the configuration options for the compression modes. ms_compress_secure Description Combining encryption with compression reduces the level of security of messages between peers. In case, both the encryption and compression are enabled, compression setting is ignored and message is not compressed. Override this setting with option. Send messages directly from the thread that generated them instead of queuing and sending from the AsyncMessenger thread. This option is known to decrease performance on systems with a lot of CPU cores, so it's disabled by default. Type Boolean Default false ms_osd_compress_mode Description Compression policy to use in messenger for communication with Ceph OSDs. Type String Default none Valid choices none or force ms_osd_compress_min_size Description Minimal message size eligible for on-wire compression. Type Integer Default 1 Ki ms_osd_compression_algorithm Description Compression algorithm for connections with OSD in order of preference Type String Default snappy Valid choices snappy , zstd , zlib , or lz4

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