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Applies to SUSE Enterprise Storage 7

8 Deploying the remaining core services using cephadm Edit source

After deploying the basic Ceph cluster, deploy core services to more cluster nodes. To make the cluster data accessible to clients, deploy additional services as well.

Currently, we support deployment of Ceph services on the command line by using the Ceph orchestrator (ceph orch subcommands).

8.1 The ceph orch command Edit source

The Ceph orchestrator command ceph orch—which is an interface to the cephadm module—will take care of listing cluster components and deploying Ceph services on new cluster nodes.

8.1.1 Displaying the orchestrator status Edit source

The following command shows the current mode and status of the Ceph orchestrator.

cephuser@adm > ceph orch status

8.1.2 Listing devices, services, and daemons Edit source

To list all disk devices, run the following:

cephuser@adm > ceph orch device ls
Hostname   Path      Type  Serial  Size   Health   Ident  Fault  Available
ses-master /dev/vdb  hdd   0d8a... 10.7G  Unknown  N/A    N/A    No
ses-min1   /dev/vdc  hdd   8304... 10.7G  Unknown  N/A    N/A    No
ses-min1   /dev/vdd  hdd   7b81... 10.7G  Unknown  N/A    N/A    No
[...]
Tip
Tip: Services and daemons

Service is a general term for a Ceph service of a specific type, for example Ceph Manager.

Daemon is a specific instance of a service, for example a process mgr.ses-min1.gdlcik running on a node called ses-min1.

To list all services known to cephadm, run:

cephuser@adm > ceph orch ls
NAME  RUNNING  REFRESHED  AGE  PLACEMENT  IMAGE NAME                  IMAGE ID
mgr       1/0  5m ago     -    <no spec>  registry.example.com/[...]  5bf12403d0bd
mon       1/0  5m ago     -    <no spec>  registry.example.com/[...]  5bf12403d0bd
Tip
Tip

You can limit the list to services on a particular node with the optional -–host parameter, and services of a particular type with the optional --service-type parameter. Acceptable types are mon, osd, mgr, mds, and rgw.

To list all running daemons deployed by cephadm, run:

cephuser@adm > ceph orch ps
NAME            HOST     STATUS   REFRESHED AGE VERSION    IMAGE ID     CONTAINER ID
mgr.ses-min1.gd ses-min1 running) 8m ago    12d 15.2.0.108 5bf12403d0bd b8104e09814c
mon.ses-min1    ses-min1 running) 8m ago    12d 15.2.0.108 5bf12403d0bd a719e0087369
Tip
Tip

To query the status of a particular daemon, use --daemon_type and --daemon_id. For OSDs, the ID is the numeric OSD ID. For MDS, the ID is the file system name:

cephuser@adm > ceph orch ps --daemon_type osd --daemon_id 0
cephuser@adm > ceph orch ps --daemon_type mds --daemon_id my_cephfs

8.2 Service and placement specification Edit source

The recommended way to specify the deployment of Ceph services is to create a YAML-formatted file with the specification of the services that you intend to deploy.

8.2.1 Creating service specifications Edit source

You can create a separate specification file for each type of service, for example:

root@master # cat nfs.yml
service_type: nfs
service_id: EXAMPLE_NFS
placement:
  hosts:
  - ses-min1
  - ses-min2
spec:
  pool: EXAMPLE_POOL
  namespace: EXAMPLE_NAMESPACE

Alternatively, you can specify multiple (or all) service types in one file—for example, cluster.yml—that describes which nodes will run specific services. Remember to separate individual service types with three dashes (---):

cephuser@adm > cat cluster.yml
service_type: nfs
service_id: EXAMPLE_NFS
placement:
  hosts:
  - ses-min1
  - ses-min2
spec:
  pool: EXAMPLE_POOL
  namespace: EXAMPLE_NAMESPACE
---
service_type: rgw
service_id: REALM_NAME.ZONE_NAME
placement:
  hosts:
  - ses-min1
  - ses-min2
  - ses-min3
---
[...]

The aforementioned properties have the following meaning:

service_type

The type of the service. It can be either a Ceph service (mon, mgr, mds, crash, osd, or rbd-mirror), a gateway (nfs or rgw), or part of the monitoring stack (alertmanager, grafana, node-exporter, or prometheus).

service_id

The name of the service. Specifications of type mon, mgr, alertmanager, grafana, node-exporter, and prometheus do not require the service_id property.

placement

Specifies which nodes will be running the service. Refer to Section 8.2.2, “Creating placement specification” for more details.

spec

Additional specification relevant for the service type.

Tip
Tip: Applying specific services

Ceph cluster services have usually a number of properties specific to them. For examples and details of individual services' specification, refer to Section 8.3, “Deploy Ceph services”.

8.2.2 Creating placement specification Edit source

To deploy Ceph services, cephadm needs to know on which nodes to deploy them. Use the placement property and list the short host names of the nodes that the service applies to:

cephuser@adm > cat cluster.yml
[...]
placement:
  hosts:
  - host1
  - host2
  - host3
[...]

8.2.3 Applying cluster specification Edit source

After you have created a full cluster.yml file with specifications of all services and their placement, you can apply the cluster by running the following command:

cephuser@adm > ceph orch apply -i cluster.yml

To view the status of the cluster, run the ceph orch status command. For more details, see Section 8.1.1, “Displaying the orchestrator status”.

8.2.4 Exporting the specification of a running cluster Edit source

Although you deployed services to the Ceph cluster by using the specification files as described in Section 8.2, “Service and placement specification”, the configuration of the cluster may diverge from the original specification during its operation. Also, you may have removed the specification files accidentally.

To retrieve a complete specification of a running cluster, run:

cephuser@adm > ceph orch ls --export
placement:
  hosts:
  - hostname: ses-min1
    name: ''
    network: ''
service_id: my_cephfs
service_name: mds.my_cephfs
service_type: mds
---
placement:
  count: 2
service_name: mgr
service_type: mgr
---
[...]
Tip
Tip

You can append the --format option to change the default yaml output format. You can select from json, json-pretty, or yaml. For example:

ceph orch ls --export --format json

8.3 Deploy Ceph services Edit source

After the basic cluster is running, you can deploy Ceph services to additional nodes.

8.3.1 Deploying Ceph Monitors and Ceph Managers Edit source

Ceph cluster has three or five MONs deployed across different nodes. If there are five or more nodes in the cluster, we recommend deploying five MONs. A good practice is to have MGRs deployed on the same nodes as MONs.

Important
Important: Include Bootstrap MON

When deploying MONs and MGRs, remember to include the first MON that you added when configuring the basic cluster in Section 7.2.5, “Specifying first MON/MGR node”.

To deploy MONs, apply the following specification:

service_type: mon
placement:
  hosts:
  - ses-min1
  - ses-min2
  - ses-min3
Note
Note

If you need to add another node, append the host name to the same YAML list. For example:

service_type: mon
placement:
 hosts:
 - ses-min1
 - ses-min2
 - ses-min3
 - ses-min4

Similarly, to deploy MGRs, apply the following specification:

Important
Important

Ensure your deployment has at least three Ceph Managers in each deployment.

service_type: mgr
placement:
  hosts:
  - ses-min1
  - ses-min2
  - ses-min3
Tip
Tip

If MONs or MGRs are not on the same subnet, you need to append the subnet addresses. For example:

service_type: mon
placement:
  hosts:
  - ses-min1:10.1.2.0/24
  - ses-min2:10.1.5.0/24
  - ses-min3:10.1.10.0/24

8.3.2 Deploying Ceph OSDs Edit source

Important
Important: When Storage Device is Available

A storage device is considered available if all of the following conditions are met:

  • The device has no partitions.

  • The device does not have any LVM state.

  • The device is not be mounted.

  • The device does not contain a file system.

  • The device does not contain a BlueStore OSD.

  • The device is larger than 5 GB.

If the above conditions are not met, Ceph refuses to provision such OSDs.

There are two ways you can deploy OSDs:

  • Tell Ceph to consume all available and unused storage devices:

    cephuser@adm > ceph orch apply osd --all-available-devices
  • Use DriveGroups (see Section 13.4.3, “Adding OSDs using DriveGroups specification”) to create OSD specification describing devices that will be deployed based on their properties, such as device type (SSD or HDD), device model names, size, or the nodes on which the devices exist. Then apply the specification by running the following command:

    cephuser@adm > ceph orch apply osd -i drive_groups.yml

8.3.3 Deploying Metadata Servers Edit source

CephFS requires one or more Metadata Server (MDS) services. To create a CephFS, first create MDS servers by applying the following specification:

Note
Note

Ensure you have at least two pools, one for CephFS data and one for CephFS metadata, created before applying the following specification.

service_type: mds
service_id: CEPHFS_NAME
placement:
  hosts:
  - ses-min1
  - ses-min2
  - ses-min3

After MDSs are functional, create the CephFS:

ceph fs new CEPHFS_NAME metadata_pool data_pool

8.3.4 Deploying Object Gateways Edit source

cephadm deploys an Object Gateway as a collection of daemons that manage a particular realm and zone.

You can either relate an Object Gateway service to already existing realm and zone, (refer to Section 21.13, “Multisite Object Gateways” for more details), or you can specify a non-existing REALM_NAME and ZONE_NAME and they will be created automatically after you apply the following configuration:

service_type: rgw
service_id: REALM_NAME.ZONE_NAME
placement:
  hosts:
  - ses-min1
  - ses-min2
  - ses-min3
spec:
  rgw_realm: RGW_REALM
  rgw_zone: RGW_ZONE

8.3.4.1 Using secure SSL access Edit source

To use a secure SSL connection to the Object Gateway, you need a pair of valid SSL certificate and key files (see Section 21.7, “Enable HTTPS/SSL for Object Gateways” for more details). You need to enable SSL, specify a port number for SSL connections, and the SSL certificate and key files.

To enable SSL and specify the port number, include the following in your specification:

spec:
  ssl: true
  rgw_frontend_port: 443

To specify the SSL certificate and key, you can paste their contents directly into the YAML specification file. The pipe sign (|) at the end of line tells the parser to expect a multi-line string as a value. For example:

spec:
  ssl: true
  rgw_frontend_port: 443
  rgw_frontend_ssl_certificate: |
   -----BEGIN CERTIFICATE-----
   MIIFmjCCA4KgAwIBAgIJAIZ2n35bmwXTMA0GCSqGSIb3DQEBCwUAMGIxCzAJBgNV
   BAYTAkFVMQwwCgYDVQQIDANOU1cxHTAbBgNVBAoMFEV4YW1wbGUgUkdXIFNTTCBp
   [...]
   -----END CERTIFICATE-----
   rgw_frontend_ssl_key: |
   -----BEGIN PRIVATE KEY-----
   MIIJRAIBADANBgkqhkiG9w0BAQEFAASCCS4wggkqAgEAAoICAQDLtFwg6LLl2j4Z
   BDV+iL4AO7VZ9KbmWIt37Ml2W6y2YeKX3Qwf+3eBz7TVHR1dm6iPpCpqpQjXUsT9
   [...]
   -----END PRIVATE KEY-----
Tip
Tip

Instead of pasting the content of SSL certificate and key files, you can omit the rgw_frontend_ssl_certificate: and rgw_frontend_ssl_key: keywords and upload them to the configuration database:

cephuser@adm > ceph config-key set rgw/cert/REALM_NAME/ZONE_NAME.crt \
 -i SSL_CERT_FILE
cephuser@adm > ceph config-key set rgw/cert/REALM_NAME/ZONE_NAME.key \
 -i SSL_KEY_FILE

8.3.4.2 Deploying with a subcluster Edit source

Subclusters help you organize the nodes in your clusters to isolate workloads and make elastic scaling easier. If you are deploying with a subcluster, apply the following configuration:

service_type: rgw
service_id: REALM_NAME.ZONE_NAME.SUBCLUSTER
placement:
  hosts:
  - ses-min1
  - ses-min2
  - ses-min3
spec:
  rgw_realm: RGW_REALM
  rgw_zone: RGW_ZONE
  subcluster: SUBCLUSTER

8.3.5 Deploying iSCSI Gateways Edit source

cephadm deploys an iSCSI Gateway which is a storage area network (SAN) protocol that allows clients (called initiators) to send SCSI commands to SCSI storage devices (targets) on remote servers.

Apply the following configuration to deploy. Ensure trusted_ip_list contains the IP addresses of all iSCSI Gateway and Ceph Manager nodes (see the example output below).

Note
Note

Ensure the pool is created before applying the following specification.

service_type: iscsi
service_id: EXAMPLE_ISCSI
placement:
  hosts:
  - ses-min1
  - ses-min2
  - ses-min3
spec:
  pool: EXAMPLE_POOL
  api_user: EXAMPLE_USER
  api_password: EXAMPLE_PASSWORD
  trusted_ip_list: "IP_ADDRESS_1,IP_ADDRESS_2"
Note
Note

Ensure the IPs listed for trusted_ip_list do not have a space after the comma separation.

8.3.5.1 Secure SSL configuration Edit source

To use a secure SSL connection between the Ceph Dashboard and the iSCSI target API, you need a pair of valid SSL certificate and key files. These can be either CA-issued or self-signed (see Section 10.1.1, “Creating self-signed certificates”). To enable SSL, include the api_secure: true setting in your specification file:

spec:
  api_secure: true

To specify the SSL certificate and key, you can paste the content directly into the YAML specification file. The pipe sign (|) at the end of line tells the parser to expect a multi-line string as a value. For example:

spec:
  pool: EXAMPLE_POOL
  api_user: EXAMPLE_USER
  api_password: EXAMPLE_PASSWORD
  trusted_ip_list: "IP_ADDRESS_1,IP_ADDRESS_2"
  api_secure: true
  ssl_cert: |
    -----BEGIN CERTIFICATE-----
    MIIDtTCCAp2gAwIBAgIYMC4xNzc1NDQxNjEzMzc2MjMyXzxvQ7EcMA0GCSqGSIb3
    DQEBCwUAMG0xCzAJBgNVBAYTAlVTMQ0wCwYDVQQIDARVdGFoMRcwFQYDVQQHDA5T
    [...]
    -----END CERTIFICATE-----
  ssl_key: |
    -----BEGIN PRIVATE KEY-----
    MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQC5jdYbjtNTAKW4
    /CwQr/7wOiLGzVxChn3mmCIF3DwbL/qvTFTX2d8bDf6LjGwLYloXHscRfxszX/4h
    [...]
    -----END PRIVATE KEY-----

8.3.6 Deploying NFS Ganesha Edit source

Important
Important

NFS Ganesha supports NFS version 4.1 and newer. It does not support NFS version 3.

cephadm deploys NFS Ganesha using a pre-defined RADOS pool and an optional name-space. To deploy NFS Ganesha, apply the following specification:

Note
Note

You need to have a pre-defined RADOS pool otherwise the ceph orch apply operation will fail. For more information on creating a pool, see Section 18.1, “Creating a pool”.

service_type: nfs
service_id: EXAMPLE_NFS
placement:
  hosts:
  - ses-min1
  - ses-min2
spec:
  pool: EXAMPLE_POOL
  namespace: EXAMPLE_NAMESPACE
  • EXAMPLE_NFS with an arbitrary string that identifies the NFS export.

  • EXAMPLE_POOL with the name of the pool where the NFS Ganesha RADOS configuration object will be stored.

  • EXAMPLE_NAMESPACE (optional) with the desired Object Gateway NFS namespace (for example, ganesha).

8.3.7 Deploying rbd-mirror Edit source

The rbd-mirror service takes care of synchronizing RADOS Block Device images between two Ceph clusters (for more details, see Section 20.4, “RBD image mirrors”). To deploy rbd-mirror, use the following specification:

service_type: rbd-mirror
service_id: EXAMPLE_RBD_MIRROR
placement:
  hosts:
  - ses-min3

8.3.8 Deploying the monitoring stack Edit source

The monitoring stack consists of Prometheus, Prometheus exporters, Prometheus Alertmanager, and Grafana. Ceph Dashboard makes use of these components to store and visualize detailed metrics on cluster usage and performance.

Tip
Tip

If your deployment requires custom or locally served container images of the monitoring stack services, refer to Section 16.1, “Configuring custom or local images”.

To deploy the monitoring stack, follow these steps:

  1. Enable the prometheus module in the Ceph Manager daemon. This exposes the internal Ceph metrics so that Prometheus can read them:

    cephuser@adm > ceph mgr module enable prometheus
    Note
    Note

    Ensure this command is run before Prometheus is deployed. If the command was not run before the deployment, you must redeploy Prometheus to update Prometheus' configuration:

    cephuser@adm > ceph orch redeploy prometheus
  2. Create a specification file (for example monitoring.yaml) with a content similar to the following:

    service_type: prometheus
    placement:
      hosts:
      - ses-min2
    ---
    service_type: node-exporter
    ---
    service_type: alertmanager
    placement:
      hosts:
      - ses-min4
    ---
    service_type: grafana
    placement:
      hosts:
      - ses-min3
  3. Apply monitoring services by running:

    cephuser@adm > ceph orch apply -i monitoring.yaml

    It may take a minute or two for the monitoring services to be deployed.

Important
Important

Prometheus, Grafana, and the Ceph Dashboard are all automatically configured to talk to each other, resulting in a fully functional Grafana integration in the Ceph Dashboard when deployed as described above.

The only exception to this rule is monitoring with RBD images. See Section 16.5.4, “Enabling RBD-image monitoring” for more information.

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