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Release Notes8.0 Release NotesBefore You BeginCompatibility GuideRed Hat Ceph Storage and Its Compatibility With Other ProductsHardware GuideHardware selection recommendations for Red Hat Ceph StorageArchitecture GuideGuide on Red Hat Ceph Storage ArchitectureData Security and Hardening GuideRed Hat Ceph Storage Data Security and Hardening GuideConfiguration GuideConfiguration settings for Red Hat Ceph StorageInstallingInstallation GuideInstalling Red Hat Ceph Storage on Red Hat Enterprise LinuxEdge GuideGuide on Edge Clusters for Red Hat Ceph StorageUpgradingUpgrade GuideUpgrading a Red Hat Ceph Storage ClusterGetting StartedGetting Started GuideGuide on getting started with Red Hat Ceph StorageCeph Clients and SolutionsFile System GuideConfiguring and Mounting Ceph File SystemsStorage AdministrationOperations GuideOperational tasks for Red Hat Ceph StorageAdministration GuideAdministration of Red Hat Ceph StorageStorage Strategies GuideCreating storage strategies for Red Hat Ceph Storage clustersMonitoringDashboard GuideMonitoring Ceph Cluster with Ceph DashboardTroubleshootingTroubleshooting GuideTroubleshooting Red Hat Ceph StorageAPI and Resource ReferenceDeveloper GuideUsing the various application programming interfaces for Red Hat Ceph StorageObject Gateway GuideDeploying, configuring, and administering a Ceph Object GatewayBlock Device GuideManaging, creating, configuring, and using Red Hat Ceph Storage Block DevicesBlock Device to OpenStack GuideConfiguring Ceph, QEMU, libvirt and OpenStack to use Ceph as a back end for OpenStack.

Red Hat Ceph Storage 7

Bootstrap. Root-level access to the host on which the dashboard needs to be enabled. Procedure Log into the Cephadm shell: Example[root@host01 ~]# cephadm shell Check the Ceph Manager services: Example[ceph: root@host01 /]# ceph mgr services{ "prometheus": " You can see that the Dashboard URL is not configured. Enable the dashboard module: Example[ceph: root@host01 /]# ceph mgr module enable dashboard Create the self-signed certificate for the dashboard access: Example[ceph: root@host01 /]# ceph dashboard create-self-signed-cert You can disable the certificate verification to avoid certification errors. Check the Ceph Manager services: Example[ceph: root@host01 /]# ceph mgr services{ "dashboard": " "prometheus": " Create the admin user and password to access the Red Hat Ceph Storage dashboard: Syntaxecho -n "PASSWORD" > PASSWORD_FILEceph dashboard ac-user-create admin -i PASSWORD_FILE administrator Example[ceph: root@host01 /]# echo -n "p@ssw0rd" > password.txt[ceph: root@host01 /]# ceph dashboard ac-user-create admin -i password.txt administrator Enable the monitoring stack. See the Enabling monitoring stack section in the Red Hat Ceph Storage Dashboard Guide for details. 2.11. Creating an admin account for syncing users to the Ceph dashboard You have to create an admin account to synchronize users to the Ceph dashboard. After creating the account, use Red Hat Single Sign-on (SSO) to synchronize users to the Ceph dashboard. See the Syncing users to the Ceph dashboard using Red Hat Single Sign-On section in the Red Hat Ceph Storage Dashboard Guide. Prerequisites A running Red Hat Ceph Storage cluster. Dashboard is installed. Admin level access to the dashboard. Users are added to the dashboard. Root-level access on all the hosts. Java OpenJDK installed. For more information, see the Installing a JRE on RHEL by using yum section of the Installing and using OpenJDK 8 for RHEL guide for OpenJDK on the Red Hat Customer Portal. Red hat Single Sign-On installed from a ZIP file. See the Installing RH-SSO from a ZIP File section of the Server Installation and Configuration Guide for Red Hat Single Sign-On on the Red Hat Customer Portal. Procedure Download the Red Hat Single Sign-On 7.4.0 Server on the system where Red Hat Ceph Storage is installed. Unzip the folder: [root@host01 ~]# unzip rhsso-7.4.0.zip Navigate to the standalone/configuration directory and open the standalone.xml for editing: [root@host01 ~]# cd standalone/configuration[root@host01 configuration]# vi standalone.xml From the bin directory of the newly created rhsso-7.4.0 folder, run the add-user-keycloak script to add the initial administrator user: [root@host01 bin]# ./add-user-keycloak.sh -u admin Replace all instances of localhost and two instances of 127.0.0.1 with the IP address of the machine where Red Hat SSO is installed. Start the server. From the bin directory of rh-sso-7.4 folder, run the standalone boot script: [root@host01 bin]# ./standalone.sh Create the admin account in https: IP_ADDRESS :8080/auth with a username and password: You have

Red Hat Ceph Storage 5

With options. You can view the limits and the current memory consumed by each daemon from the ceph orch ps output under MEM LIMIT column. The default setting of osd_memory_target_autotune true is unsuitable for hyperconverged infrastructures where compute and Ceph storage services are colocated. In a hyperconverged infrastructure, the autotune_memory_target_ratio can be set to 0.2 to reduce the memory consumption of Ceph. Example[ceph: root@host01 /]# ceph config set mgr mgr/cephadm/autotune_memory_target_ratio 0.2 You can manually set a specific memory target for an OSD in the storage cluster. Example[ceph: root@host01 /]# ceph config set osd.123 osd_memory_target 7860684936 You can manually set a specific memory target for an OSD host in the storage cluster. Syntaxceph config set osd/host:HOSTNAME osd_memory_target TARGET_BYTES Example[ceph: root@host01 /]# ceph config set osd/host:host01 osd_memory_target 1000000000 Enabling osd_memory_target_autotune overwrites existing manual OSD memory target settings. To prevent daemon memory from being tuned even when the osd_memory_target_autotune option or other similar options are enabled, set the _no_autotune_memory label on the host. Syntaxceph orch host label add HOSTNAME _no_autotune_memory You can exclude an OSD from memory autotuning by disabling the autotune option and setting a specific memory target. Example[ceph: root@host01 /]# ceph config set osd.123 osd_memory_target_autotune false[ceph: root@host01 /]# ceph config set osd.123 osd_memory_target 16G 1.9. MDS Memory Cache Limit MDS servers keep their metadata in a separate storage pool, named cephfs_metadata, and are the users of Ceph OSDs. For Ceph File Systems, MDS servers have to support an entire Red Hat Ceph Storage cluster, not just a single storage device within the storage cluster, so their memory requirements can be significant, particularly if the workload consists of small-to-medium-size files, where the ratio of metadata to data is much higher. Example: Set the mds_cache_memory_limit to 2000000000 bytes ceph_conf_overrides: mds: mds_cache_memory_limit=2000000000 For a large Red Hat Ceph Storage cluster with a metadata-intensive workload, do not put an MDS server on the same node as other memory-intensive services, doing so gives you the option to allocate more memory to MDS, for example, sizes greater than 100 GB. See the general Ceph configuration options in Configuration options for specific option descriptions and usage. Chapter 2. Ceph network configuration As a storage administrator, you must understand the network environment that the Red Hat Ceph Storage cluster will operate in, and configure the Red Hat Ceph Storage accordingly. Understanding and configuring the Ceph network options will ensure optimal performance and reliability of the overall storage cluster. Prerequisites Network connectivity. Installation of the Red Hat Ceph Storage software. 2.1. Network configuration for Ceph Network configuration is critical for building a high performance Red Hat Ceph Storage cluster. The Ceph storage cluster does not perform request routing or dispatching on behalf of the Ceph client. Instead, Ceph clients make requests directly to Ceph OSD daemons. Ceph OSDs perform data replication on behalf of Ceph clients, which means replication and other factors impose additional loads on the networks of Ceph storage clusters. Ceph has one network configuration requirement that applies to all daemons. The Ceph configuration file must specify the. Red Hat Ceph Storage (RHCS) 5 Red Hat Ceph Storage (RHCS) 6 Red Hat Ceph Storage (RHCS) 7 Red Hat Ceph Storage (RHCS) 8. Subscriber exclusive content. A Red Hat

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The [global] section of the configuration file. Deployment tools usually generate the fsid and store it in the monitor map, so the value may not appear in a configuration file. The fsid makes it possible to run daemons for multiple clusters on the same hardware. Do not set this value if you use a deployment tool that does it for you. 3.9. Ceph Monitor data store Ceph provides a default path where Ceph monitors store data. Red Hat recommends running Ceph monitors on separate drives from Ceph OSDs for optimal performance in a production Red Hat Ceph Storage cluster. A dedicated /var/lib/ceph partition should be used for the MON database with a size between 50 and 100 GB. Ceph monitors call the fsync() function often, which can interfere with Ceph OSD workloads. Ceph monitors store their data as key-value pairs. Using a data store prevents recovering Ceph monitors from running corrupted versions through Paxos, and it enables multiple modification operations in one single atomic batch, among other advantages. Red Hat does not recommend changing the default data location. If you modify the default location, make it uniform across Ceph monitors by setting it in the [mon] section of the configuration file. 3.10. Ceph storage capacity When a Red Hat Ceph Storage cluster gets close to its maximum capacity (specifies by the mon_osd_full_ratio parameter), Ceph prevents you from writing to or reading from Ceph OSDs as a safety measure to prevent data loss. Therefore, letting a production Red Hat Ceph Storage cluster approach its full ratio is not a good practice, because it sacrifices high availability. The default full ratio is .95, or 95% of capacity. This a very aggressive setting for a test cluster with a small number of OSDs. When monitoring a cluster, be alert to warnings related to the nearfull ratio. This means that a failure of some OSDs could result in a temporary service disruption if one or more OSDs fails. Consider adding more OSDs to increase storage capacity. A common scenario for test clusters involves a system administrator removing a Ceph OSD from the Red Hat Ceph Storage cluster to watch the cluster re-balance. Then, removing another Ceph OSD, and so on until the Red Hat Ceph Storage cluster eventually reaches the full ratio and locks up. Red Hat recommends a bit of capacity planning even with a test cluster. Planning enables you to gauge how much spare capacity you will need in to maintain high availability. Ideally, you want to plan for a series of Ceph OSD failures where the cluster can recover to an active + clean state without replacing those Ceph OSDs immediately. You can run a cluster in an active + degraded state, but this is not ideal for normal operating conditions. The following diagram depicts a simplistic Red Hat Ceph Storage cluster containing 33 Ceph Nodes with one Ceph OSD per host, each Ceph OSD Daemon reading from and writing to a 3TB drive. So this exemplary Red Hat Ceph Storage

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Red Hat Ceph Storage 8Configuration settings for Red Hat Ceph StorageAbstract This document provides instructions for configuring Red Hat Ceph Storage at boot time and run time. It also provides configuration reference information. Red Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright's message. Chapter 1. The basics of Ceph configuration As a storage administrator, you need to have a basic understanding of how to view the Ceph configuration, and how to set the Ceph configuration options for the Red Hat Ceph Storage cluster. You can view and set the Ceph configuration options at runtime. Prerequisites Installation of the Red Hat Ceph Storage software. 1.1. Ceph configuration All Red Hat Ceph Storage clusters have a configuration, which defines: Cluster Identity Authentication settings Ceph daemons Network configuration Node names and addresses Paths to keyrings Paths to OSD log files Other runtime options A deployment tool, such as cephadm, will typically create an initial Ceph configuration file for you. However, you can create one yourself if you prefer to bootstrap a Red Hat Ceph Storage cluster without using a deployment tool. 1.2. The Ceph configuration database The Ceph Monitor manages a configuration database of Ceph options that centralize configuration management by storing configuration options for the entire storage cluster. By centralizing the Ceph configuration in a database, this simplifies storage cluster administration. The priority order that Ceph uses to set options is: Compiled-in default values Ceph cluster configuration database Local ceph.conf file Runtime override, using the ceph daemon DAEMON-NAME config set or ceph tell DAEMON-NAME injectargs commands There are still a few Ceph options that can be defined in the local Ceph configuration file, which is /etc/ceph/ceph.conf by default. However, ceph.conf has been deprecated for Red Hat Ceph Storage 8. cephadm uses a basic ceph.conf file that only contains a minimal set of options for connecting to Ceph Monitors, authenticating, and fetching configuration information. In most cases, cephadm uses only the mon_host option. To avoid using ceph.conf only for the mon_host option, use DNS SRV records to perform operations with Monitors. Red Hat recommends that you use the assimilate-conf administrative command to move valid options into the configuration database from the ceph.conf file. For more information about assimilate-conf, see Administrative Commands. Ceph allows you to make changes to the configuration of a daemon at runtime. This capability can be useful for increasing or decreasing the logging output, by enabling or disabling debug settings, and can even be used for runtime optimization. When the same option exists in the configuration database and the Ceph configuration file, the configuration database option has a lower priority than what is set in the Ceph configuration file. Sections and Masks Just as you can configure Ceph options globally, per daemon type, or by a specific

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We trim its old states. Boolean True mon_osd_mapping_pgs_per_chunk We calculate the mapping from the placement group to OSDs in chunks. This option specifies the number of placement groups per chunk. Integer 4096 rados_mon_op_timeout Number of seconds to wait for a response from the monitor before returning an error from a rados operation. 0 means at limit, or no wait time. Double 0 Appendix D. Cephx configuration options The following are Cephx configuration options that can be set up during deployment. auth_cluster_requiredDescription If enabled, the Red Hat Ceph Storage cluster daemons, ceph-mon and ceph-osd, must authenticate with each other. Valid settings are cephx or none. Type String Required No Default cephx. auth_service_requiredDescription If enabled, the Red Hat Ceph Storage cluster daemons require Ceph clients to authenticate with the Red Hat Ceph Storage cluster in order to access Ceph services. Valid settings are cephx or none. Type String Required No Default cephx. auth_client_requiredDescription If enabled, the Ceph client requires the Red Hat Ceph Storage cluster to authenticate with the Ceph client. Valid settings are cephx or none. Type String Required No Default cephx. keyringDescription The path to the keyring file. Type String Required No Default /etc/ceph/$cluster.$name.keyring,/etc/ceph/$cluster.keyring,/etc/ceph/keyring,/etc/ceph/keyring.bin keyfileDescription The path to a key file (that is. a file containing only the key). Type String Required No Default None keyDescription The key (that is, the text string of the key itself). Not recommended. Type String Required No Default None ceph-monLocation $mon_data/keyring Capabilities mon 'allow *' ceph-osdLocation $osd_data/keyring Capabilities mon 'allow profile osd' osd 'allow *' radosgwLocation $rgw_data/keyring Capabilities mon 'allow rwx' osd 'allow rwx' cephx_require_signaturesDescription If set to true, Ceph requires signatures on all message traffic between the Ceph client and the Red Hat Ceph Storage cluster, and between daemons comprising the Red Hat Ceph Storage cluster. Type Boolean Required No Default false cephx_cluster_require_signaturesDescription If set to true, Ceph requires signatures on all message traffic between Ceph daemons comprising the Red Hat Ceph Storage cluster. Type Boolean Required No Default false cephx_service_require_signaturesDescription If set to true, Ceph requires signatures on all message traffic between Ceph clients and the Red Hat Ceph Storage cluster. Type Boolean Required No Default false cephx_sign_messagesDescription If the Ceph version supports message signing, Ceph will sign all messages so they cannot be spoofed. Type Boolean Default true auth_service_ticket_ttlDescription When the Red Hat Ceph Storage cluster sends a Ceph client a ticket for authentication, the cluster assigns the ticket a time to live. Type Double Default 60*60 Appendix E. Pools, placement groups, and CRUSH configuration options The Ceph options that govern pools, placement groups, and the CRUSH algorithm. Configuration optionDescriptionTypeDefault mon_allow_pool_delete Allows a monitor to delete a pool. In RHCS 3 and later releases, the monitor cannot delete the pool by default as an added measure to protect data. Boolean false mon_max_pool_pg_num The maximum number of placement groups per pool. Integer 65536 mon_pg_create_interval Number of seconds between PG creation in the same Ceph OSD Daemon. Float 30.0 mon_pg_stuck_threshold Number of seconds after which PGs can be considered as being stuck. 32-bit

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Red Hat Ceph Storage 1.2.3Architecture GuideAbstract This document is an architecture guide for Red Hat Ceph Storage. Preface Red Hat Ceph is a distributed data object store designed to provide excellent performance, reliability and scalability. Distributed object stores are the future of storage, because they accommodate unstructured data, and because clients can use modern object interfaces and legacy interfaces simultaneously. For example: Native language binding interfaces (C/C++, Java, Python) RESTful interfaces (S3/Swift) Block device interfaces Filesystem interfaces The power of Red Hat Ceph can transform your organization’s IT infrastructure and your ability to manage vast amounts of data, especially for cloud computing platforms like RHEL OSP. Red Hat Ceph delivers extraordinary scalability–thousands of clients accessing petabytes to exabytes of data and beyond. At the heart of every Ceph deployment is the Ceph Storage Cluster. It consists of two types of daemons: Ceph OSD Daemon: Ceph OSDs store data on behalf of Ceph clients. Additionally, Ceph OSDs utilize the CPU and memory of Ceph nodes to perform data replication, rebalancing, recovery, monitoring and reporting functions. Ceph Monitor: A Ceph monitor maintains a master copy of the Ceph storage cluster map with the current state of the storage cluster. Ceph client interfaces read data from and write data to the Ceph storage cluster. Clients need the following data to communicate with the Ceph storage cluster: The Ceph configuration file, or the cluster name (usually ceph) and monitor address The pool name The user name and the path to the secret key. Ceph. Red Hat Ceph Storage (RHCS) 5 Red Hat Ceph Storage (RHCS) 6 Red Hat Ceph Storage (RHCS) 7 Red Hat Ceph Storage (RHCS) 8. Subscriber exclusive content. A Red Hat Downloads Red Hat Console Get Support Products Top Products Red Hat Enterprise Linux Red Hat Ceph Storage (RHCS) 5; Red Hat Ceph Storage (RHCS) 6; Red Hat Ceph Storage

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Chapter 1. Red Hat Ceph Storage Red Hat Ceph Storage is a scalable, open, software-defined storage platform that combines an enterprise-hardened version of the Ceph storage system, with a Ceph management platform, deployment utilities, and support services. Red Hat Ceph Storage is designed for cloud infrastructure and web-scale object storage. Red Hat Ceph Storage clusters consist of the following types of nodes: Ceph Monitor Each Ceph Monitor node runs the ceph-mon daemon, which maintains a master copy of the storage cluster map. The storage cluster map includes the storage cluster topology. A client connecting to the Ceph storage cluster retrieves the current copy of the storage cluster map from the Ceph Monitor, which enables the client to read from and write data to the storage cluster. The storage cluster can run with only one Ceph Monitor; however, to ensure high availability in a production storage cluster, Red Hat will only support deployments with at least three Ceph Monitor nodes. Red Hat recommends deploying a total of 5 Ceph Monitors for storage clusters exceeding 750 Ceph OSDs. Ceph Manager The Ceph Manager daemon, ceph-mgr, co-exists with the Ceph Monitor daemons running on Ceph Monitor nodes to provide additional services. The Ceph Manager provides an interface for other monitoring and management systems using Ceph Manager modules. Running the Ceph Manager daemons is a requirement for normal storage cluster operations. Ceph OSD Each Ceph Object Storage Device (OSD) node runs the ceph-osd daemon, which interacts with logical disks attached to the node. The storage cluster stores data on these Ceph OSD nodes. Ceph can run with very few OSD nodes, of which the default is three, but production storage clusters realize better performance beginning at modest scales. For example, 50 Ceph OSDs in a storage cluster. Ideally, a Ceph storage cluster has multiple OSD nodes, allowing for the possibility to isolate failure domains by configuring the CRUSH map accordingly. Ceph MDS Each Ceph Metadata Server (MDS) node runs the ceph-mds daemon, which manages metadata related to files stored on the Ceph File System (CephFS). The Ceph MDS daemon also coordinates access to the shared storage cluster. Ceph Object Gateway Ceph Object Gateway node runs the ceph-radosgw daemon, and is an object storage interface built on top of librados to provide applications with a RESTful access point to the Ceph storage cluster. The Ceph Object Gateway supports two interfaces: S3 Provides object storage functionality with an interface that is compatible with a large subset of the Amazon S3 RESTful API. Swift Provides object storage functionality with an interface that is compatible with a large subset of the OpenStack Swift API.

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Ceph osd unset pause4.3. Disabling Cephx The following procedure describes how to disable Cephx. If your cluster environment is relatively safe, you can offset the computation expense of running authentication. Red Hat recommends enabling authentication. However, it may be easier during setup or troubleshooting to temporarily disable authentication. Prerequisites A running Red Hat Ceph Storage cluster. Root-level access to the Ceph Monitor node. Procedure Disable cephx authentication by setting the following options in the [global] section of the Ceph configuration file: Exampleauth_cluster_required = noneauth_service_required = noneauth_client_required = none Start or restart the Ceph storage cluster. 4.4. Cephx user keyrings When you run Ceph with authentication enabled, the ceph administrative commands and Ceph clients require authentication keys to access the Ceph storage cluster. The most common way to provide these keys to the ceph administrative commands and clients is to include a Ceph keyring under the /etc/ceph/ directory. The file name is usually ceph.client.admin.keyring or $cluster.client.admin.keyring. If you include the keyring under the /etc/ceph/ directory, you do not need to specify a keyring entry in the Ceph configuration file. Red Hat recommends copying the Red Hat Ceph Storage cluster keyring file to nodes where you will run administrative commands, because it contains the client.admin key. To do so, execute the following command: # scp USER@HOSTNAME:/etc/ceph/ceph.client.admin.keyring /etc/ceph/ceph.client.admin.keyring Replace USER with the user name used on the host with the client.admin key and HOSTNAME with the host name of that host. Ensure the ceph.keyring file has appropriate permissions set on the client machine. You can specify the key itself in the Ceph configuration file using the key setting, which is not recommended, or a path to a key file using the keyfile setting. 4.5. Cephx daemon keyrings Administrative users or deployment tools might generate daemon keyrings in the same way as generating user keyrings. By default, Ceph stores daemons keyrings inside their data directory. The default keyring locations, and the capabilities necessary for the daemon to function. The monitor keyring contains a key but no capabilities, and is not part of the Ceph storage cluster auth database. The daemon data directory locations default to directories of the form: /var/lib/ceph/$type/CLUSTER-IDExample/var/lib/ceph/osd/ceph-12 You can override these locations, but it is not recommended. 4.6. Cephx message signatures Ceph provides fine-grained control so you can enable or disable signatures for service messages between the client and Ceph. You can enable or disable signatures for messages between Ceph daemons. Red Hat recommends that Ceph authenticate all ongoing messages between the entities using the session key set up for that initial authentication. Ceph kernel modules do not support signatures yet. Chapter 5. Pools, placement groups, and CRUSH configuration As a storage administrator, you can choose to use the Red Hat Ceph Storage default options for pools, placement groups, and the CRUSH algorithm or customize them for the intended workload. Prerequisites Installation of the Red Hat Ceph Storage software. 5.1. Pools placement groups and CRUSH When you create pools and set the number of placement groups for the pool, Ceph uses. Red Hat Ceph Storage (RHCS) 5 Red Hat Ceph Storage (RHCS) 6 Red Hat Ceph Storage (RHCS) 7 Red Hat Ceph Storage (RHCS) 8. Subscriber exclusive content. A Red Hat

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Network messenger Messenger is the Ceph network layer implementation. Red Hat supports two messenger types: simple async In Red Hat Ceph Storage 7 and higher, async is the default messenger type. To change the messenger type, specify the ms_type configuration setting in the [global] section of the Ceph configuration file. For the async messenger, Red Hat supports the posix transport type, but does not currently support rdma or dpdk. By default, the ms_type setting in Red Hat Ceph Storage reflects async+posix, where async is the messenger type and posix is the transport type. SimpleMessenger The SimpleMessenger implementation uses TCP sockets with two threads per socket. Ceph associates each logical session with a connection. A pipe handles the connection, including the input and output of each message. While SimpleMessenger is effective for the posix transport type, it is not effective for other transport types such as rdma or dpdk. AsyncMessenger Consequently, AsyncMessenger is the default messenger type for Red Hat Ceph Storage 7 or higher. For Red Hat Ceph Storage 7 or higher, the AsyncMessenger implementation uses TCP sockets with a fixed-size thread pool for connections, which should be equal to the highest number of replicas or erasure-code chunks. The thread count can be set to a lower value if performance degrades due to a low CPU count or a high number of OSDs per server. Red Hat does not support other transport types such as rdma or dpdk at this time. Additional Resources See the AsyncMessenger options in Red Hat Ceph Storage Configuration Guide, Appendix B for specific option descriptions and usage. See the Red Hat Ceph Storage Architecture Guide for details about using on-wire encryption with the Ceph messenger version 2 protocol. 2.3. Configuring a public network To configure Ceph networks, use the config set command within the cephadm shell. Note that the IP addresses you set in your network configuration are different from the public-facing IP addresses that network clients might use to access your service. Ceph functions perfectly well with only a public network. However, Ceph allows you to establish much more specific criteria, including multiple IP networks for your public network. You can also establish a separate, private cluster network to handle OSD heartbeat, object replication, and recovery traffic. For more information about the private network, see Configuring a private network. Ceph uses CIDR notation for subnets, for example, 10.0.0.0/24. Typical internal IP networks are often 192.168.0.0/24 or 10.0.0.0/24. If you specify more than one IP address for either the public or the cluster network, the subnets within the network must be capable of routing to each other. In addition, make sure you include each IP address in your IP tables, and open ports for them as necessary. The public network configuration allows you specifically define IP addresses and subnets for the public network. Prerequisites Installation of the Red Hat Ceph Storage software. Procedure Log in to the cephadm shell: Example[root@host01 ~]# cephadm shell Configure the public network with the subnet: Syntaxceph config set mon public_network