Appendix B. Manually Installing Red Hat Ceph Storage

Important

Red Hat does not support or test upgrading manually deployed clusters. Therefore, Red Hat recommends to use Ansible to deploy a new cluster with Red Hat Ceph Storage 3. See Chapter 3, Deploying Red Hat Ceph Storage for details.

You can use command-line utilities, such as Yum, to upgrade manually deployed clusters, but Red Hat does not support or test this.

All Ceph clusters require at least one monitor, and at least as many OSDs as copies of an object stored on the cluster. Red Hat recommends using three monitors for production environments and a minimum of three Object Storage Devices (OSD).

Bootstrapping the initial monitor is the first step in deploying a Ceph storage cluster. Ceph monitor deployment also sets important criteria for the entire cluster, such as:

  • The number of replicas for pools
  • The number of placement groups per OSD
  • The heartbeat intervals
  • Any authentication requirement

Most of these values are set by default, so it is useful to know about them when setting up the cluster for production.

Installing a Ceph storage cluster by using the command line interface involves these steps:

Configuring the Network Time Protocol for Red Hat Ceph Storage

All Ceph Monitor and OSD nodes requires configuring the Network Time Protocol (NTP). Ensure that Ceph nodes are NTP peers. NTP helps preempt issues that arise from clock drift.

Note

When using Ansible to deploy a Red Hat Ceph Storage cluster, Ansible automatically installs, configures, and enables NTP.

Prerequisites

  • Network access to a valid time source.

Procedure: Configuring the Network Time Protocol for RHCS

Do the following steps on the all RHCS nodes in the storage cluster, as the root user.

  1. Install the ntp package: 

    # yum install ntp

  2. Start and enable the NTP service to be persistent across a reboot: 

    # systemctl start ntpd
# systemctl enable ntpd

  3. Ensure that NTP is synchronizing clocks properly: 

    $ ntpq -p

Additional Resources

Monitor Bootstrapping

Bootstrapping a Monitor and by extension a Ceph storage cluster, requires the following data:

Unique Identifier
The File System Identifier (fsid) is a unique identifier for the cluster. The fsid was originally used when the Ceph storage cluster was principally used for the Ceph file system. Ceph now supports native interfaces, block devices, and object storage gateway interfaces too, so fsid is a bit of a misnomer.
Cluster Name

Ceph clusters have a cluster name, which is a simple string without spaces. The default cluster name is ceph, but you can specify a different cluster name. Overriding the default cluster name is especially useful when you work with multiple clusters.

When you run multiple clusters in a multi-site architecture, the cluster name for example, us-west, us-east identifies the cluster for the current command-line session.

Note

To identify the cluster name on the command-line interface, specify the Ceph configuration file with the cluster name, for example, ceph.conf, us-west.conf, us-east.conf, and so on.

Example:

# ceph --cluster us-west.conf ...

Monitor Name
Each Monitor instance within a cluster has a unique name. In common practice, the Ceph Monitor name is the node name. Red Hat recommend one Ceph Monitor per node, and no co-locating the Ceph OSD daemons with the Ceph Monitor daemon. To retrieve the short node name, use the hostname -s command.
Monitor Map

Bootstrapping the initial Monitor requires you to generate a Monitor map. The Monitor map requires:

  • The File System Identifier (fsid)
  • The cluster name, or the default cluster name of ceph is used
  • At least one host name and its IP address.
Monitor Keyring
Monitors communicate with each other by using a secret key. You must generate a keyring with a Monitor secret key and provide it when bootstrapping the initial Monitor.
Administrator Keyring
To use the ceph command-line interface utilities, create the client.admin user and generate its keyring. Also, you must add the client.admin user to the Monitor keyring.

The foregoing requirements do not imply the creation of a Ceph configuration file. However, as a best practice, Red Hat recommends creating a Ceph configuration file and populating it with the fsid, the mon initial members and the mon host settings at a minimum.

You can get and set all of the Monitor settings at runtime as well. However, the Ceph configuration file might contain only those settings which overrides the default values. When you add settings to a Ceph configuration file, these settings override the default settings. Maintaining those settings in a Ceph configuration file makes it easier to maintain the cluster.

To bootstrap the initial Monitor, perform the following steps:

  1. Enable the Red Hat Ceph Storage 3 Monitor repository: 

    [root@monitor ~]# subscription-manager repos --enable=rhel-7-server-rhceph-3-mon-rpms

  2. On your initial Monitor node, install the ceph-mon package as root: 

    # yum install ceph-mon

  3. As root, create a Ceph configuration file in the /etc/ceph/ directory. By default, Ceph uses ceph.conf, where ceph reflects the cluster name:

    Syntax

    # touch /etc/ceph/<cluster_name>.conf

    Example

    # touch /etc/ceph/ceph.conf

  4. As root, generate the unique identifier for your cluster and add the unique identifier to the [global] section of the Ceph configuration file:

    Syntax

    # echo "[global]" > /etc/ceph/<cluster_name>.conf
# echo "fsid = `uuidgen`" >> /etc/ceph/<cluster_name>.conf

    Example

    # echo "[global]" > /etc/ceph/ceph.conf
# echo "fsid = `uuidgen`" >> /etc/ceph/ceph.conf

  5. View the current Ceph configuration file: 

    $ cat /etc/ceph/ceph.conf
[global]
fsid = a7f64266-0894-4f1e-a635-d0aeaca0e993

  6. As root, add the initial Monitor to the Ceph configuration file:

    Syntax

    # echo "mon initial members = <monitor_host_name>[,<monitor_host_name>]" >> /etc/ceph/<cluster_name>.conf

    Example

    # echo "mon initial members = node1" >> /etc/ceph/ceph.conf

  7. As root, add the IP address of the initial Monitor to the Ceph configuration file:

    Syntax

    # echo "mon host = <ip-address>[,<ip-address>]" >> /etc/ceph/<cluster_name>.conf

    Example

    # echo "mon host = 192.168.0.120" >> /etc/ceph/ceph.conf

    Note

    To use IPv6 addresses, you set the ms bind ipv6 option to true. For details, see the Bind section in the Configuration Guide for Red Hat Ceph Storage 3.

  8. As root, create the keyring for the cluster and generate the Monitor secret key:

    Syntax

    # ceph-authtool --create-keyring /tmp/<cluster_name>.mon.keyring --gen-key -n mon. --cap mon '<capabilites>'

    Example

    # ceph-authtool --create-keyring /tmp/ceph.mon.keyring --gen-key -n mon. --cap mon 'allow *'
creating /tmp/ceph.mon.keyring

  9. As root, generate an administrator keyring, generate a <cluster_name>.client.admin.keyring user and add the user to the keyring:

    Syntax

    # ceph-authtool --create-keyring /etc/ceph/<cluster_name>.client.admin.keyring --gen-key -n client.admin --set-uid=0 --cap mon '<capabilites>' --cap osd '<capabilites>' --cap mds '<capabilites>'

    Example

    # ceph-authtool --create-keyring /etc/ceph/ceph.client.admin.keyring --gen-key -n client.admin --set-uid=0 --cap mon 'allow *' --cap osd 'allow *' --cap mds 'allow'
creating /etc/ceph/ceph.client.admin.keyring

  10. As root, add the <cluster_name>.client.admin.keyring key to the <cluster_name>.mon.keyring:

    Syntax

    # ceph-authtool /tmp/<cluster_name>.mon.keyring --import-keyring /etc/ceph/<cluster_name>.client.admin.keyring

    Example

    # ceph-authtool /tmp/ceph.mon.keyring --import-keyring /etc/ceph/ceph.client.admin.keyring
importing contents of /etc/ceph/ceph.client.admin.keyring into /tmp/ceph.mon.keyring

  11. Generate the Monitor map. Specify using the node name, IP address and the fsid, of the initial Monitor and save it as /tmp/monmap:

    Syntax

    $ monmaptool --create --add <monitor_host_name> <ip-address> --fsid <uuid> /tmp/monmap

    Example

    $ monmaptool --create --add node1 192.168.0.120 --fsid a7f64266-0894-4f1e-a635-d0aeaca0e993 /tmp/monmap
monmaptool: monmap file /tmp/monmap
monmaptool: set fsid to a7f64266-0894-4f1e-a635-d0aeaca0e993
monmaptool: writing epoch 0 to /tmp/monmap (1 monitors)

  12. As root on the initial Monitor node, create a default data directory:

    Syntax

    # mkdir /var/lib/ceph/mon/<cluster_name>-<monitor_host_name>

    Example

    # mkdir /var/lib/ceph/mon/ceph-node1

  13. As root, populate the initial Monitor daemon with the Monitor map and keyring:

    Syntax

    # ceph-mon [--cluster <cluster_name>] --mkfs -i <monitor_host_name> --monmap /tmp/monmap --keyring /tmp/<cluster_name>.mon.keyring

    Example

    # ceph-mon --mkfs -i node1 --monmap /tmp/monmap --keyring /tmp/ceph.mon.keyring
ceph-mon: set fsid to a7f64266-0894-4f1e-a635-d0aeaca0e993
ceph-mon: created monfs at /var/lib/ceph/mon/ceph-node1 for mon.node1

  14. View the current Ceph configuration file: 

    # cat /etc/ceph/ceph.conf
[global]
fsid = a7f64266-0894-4f1e-a635-d0aeaca0e993
mon_initial_members = node1
mon_host = 192.168.0.120

    For more details on the various Ceph configuration settings, see the Configuration Guide for Red Hat Ceph Storage 3. The following example of a Ceph configuration file lists some of the most common configuration settings:

    Example

    [global]
fsid = <cluster-id>
mon initial members = <monitor_host_name>[, <monitor_host_name>]
mon host = <ip-address>[, <ip-address>]
public network = <network>[, <network>]
cluster network = <network>[, <network>]
auth cluster required = cephx
auth service required = cephx
auth client required = cephx
osd journal size = <n>
osd pool default size = <n>  # Write an object n times.
osd pool default min size = <n> # Allow writing n copy in a degraded state.
osd pool default pg num = <n>
osd pool default pgp num = <n>
osd crush chooseleaf type = <n>

  15. As root, create the done file:

    Syntax

    # touch /var/lib/ceph/mon/<cluster_name>-<monitor_host_name>/done

    Example

    # touch /var/lib/ceph/mon/ceph-node1/done

  16. As root, update the owner and group permissions on the newly created directory and files:

    Syntax

    # chown -R <owner>:<group> <path_to_directory>

    Example

    # chown -R ceph:ceph /var/lib/ceph/mon
# chown -R ceph:ceph /var/log/ceph
# chown -R ceph:ceph /var/run/ceph
# chown ceph:ceph /etc/ceph/ceph.client.admin.keyring
# chown ceph:ceph /etc/ceph/ceph.conf
# chown ceph:ceph /etc/ceph/rbdmap

    Note

    If the Ceph Monitor node is co-located with an OpenStack Controller node, then the Glance and Cinder keyring files must be owned by glance and cinder respectively. For example: 

    # ls -l /etc/ceph/
...
-rw-------.  1 glance glance      64 <date> ceph.client.glance.keyring
-rw-------.  1 cinder cinder      64 <date> ceph.client.cinder.keyring
...

  17. For storage clusters with custom names, as root, add the the following line:

    Syntax

    # echo "CLUSTER=<custom_cluster_name>" >> /etc/sysconfig/ceph

    Example

    # echo "CLUSTER=test123" >> /etc/sysconfig/ceph

  18. As root, start and enable the ceph-mon process on the initial Monitor node:

    Syntax

    # systemctl enable ceph-mon.target
# systemctl enable ceph-mon@<monitor_host_name>
# systemctl start ceph-mon@<monitor_host_name>

    Example

    # systemctl enable ceph-mon.target
# systemctl enable ceph-mon@node1
# systemctl start ceph-mon@node1

  19. As root, verify the monitor daemon is running:

    Syntax

    # systemctl status ceph-mon@<monitor_host_name>

    Example

    # systemctl status ceph-mon@node1
● ceph-mon@node1.service - Ceph cluster monitor daemon
   Loaded: loaded (/usr/lib/systemd/system/ceph-mon@.service; enabled; vendor preset: disabled)
   Active: active (running) since Wed 2018-06-27 11:31:30 PDT; 5min ago
 Main PID: 1017 (ceph-mon)
   CGroup: /system.slice/system-ceph\x2dmon.slice/ceph-mon@node1.service
           └─1017 /usr/bin/ceph-mon -f --cluster ceph --id node1 --setuser ceph --setgroup ceph

Jun 27 11:31:30 node1 systemd[1]: Started Ceph cluster monitor daemon.
Jun 27 11:31:30 node1 systemd[1]: Starting Ceph cluster monitor daemon...

To add more Red Hat Ceph Storage Monitors to the storage cluster, see the Adding a Monitor section in the Administration Guide for Red Hat Ceph Storage 3.

OSD Bootstrapping

Once you have your initial monitor running, you can start adding the Object Storage Devices (OSDs). Your cluster cannot reach an active + clean state until you have enough OSDs to handle the number of copies of an object.

The default number of copies for an object is three. You will need three OSD nodes at minimum. However, if you only want two copies of an object, therefore only adding two OSD nodes, then update the osd pool default size and osd pool default min size settings in the Ceph configuration file.

For more details, see the OSD Configuration Reference section in the Configuration Guide for Red Hat Ceph Storage 3.

After bootstrapping the initial monitor, the cluster has a default CRUSH map. However, the CRUSH map does not have any Ceph OSD daemons mapped to a Ceph node.

To add an OSD to the cluster and updating the default CRUSH map, execute the following on each OSD node:

  1. Enable the Red Hat Ceph Storage 3 OSD repository: 

    [root@osd ~]# subscription-manager repos --enable=rhel-7-server-rhceph-3-osd-rpms

  2. As root, install the ceph-osd package on the Ceph OSD node: 

    # yum install ceph-osd

  3. Copy the Ceph configuration file and administration keyring file from the initial Monitor node to the OSD node:

    Syntax

    # scp <user_name>@<monitor_host_name>:<path_on_remote_system> <path_to_local_file>

    Example

    # scp root@node1:/etc/ceph/ceph.conf /etc/ceph
# scp root@node1:/etc/ceph/ceph.client.admin.keyring /etc/ceph

  4. Generate the Universally Unique Identifier (UUID) for the OSD: 

    $ uuidgen
b367c360-b364-4b1d-8fc6-09408a9cda7a

  5. As root, create the OSD instance:

    Syntax

    # ceph osd create <uuid> [<osd_id>]

    Example

    # ceph osd create b367c360-b364-4b1d-8fc6-09408a9cda7a
0

    Note

    This command outputs the OSD number identifier needed for subsequent steps.

  6. As root, create the default directory for the new OSD:

    Syntax

    # mkdir /var/lib/ceph/osd/<cluster_name>-<osd_id>

    Example

    # mkdir /var/lib/ceph/osd/ceph-0

  7. As root, prepare the drive for use as an OSD, and mount it to the directory you just created. Create a partition for the Ceph data and journal. The journal and the data partitions can be located on the same disk. This example is using a 15 GB disk:

    Syntax

    # parted <path_to_disk> mklabel gpt
# parted <path_to_disk> mkpart primary 1 10000
# mkfs -t <fstype> <path_to_partition>
# mount -o noatime <path_to_partition> /var/lib/ceph/osd/<cluster_name>-<osd_id>
# echo "<path_to_partition>  /var/lib/ceph/osd/<cluster_name>-<osd_id>   xfs defaults,noatime 1 2" >> /etc/fstab

    Example

    # parted /dev/sdb mklabel gpt
# parted /dev/sdb mkpart primary 1 10000
# parted /dev/sdb mkpart primary 10001 15000
# mkfs -t xfs /dev/sdb1
# mount -o noatime /dev/sdb1 /var/lib/ceph/osd/ceph-0
# echo "/dev/sdb1 /var/lib/ceph/osd/ceph-0  xfs defaults,noatime 1 2" >> /etc/fstab

  8. As root, initialize the OSD data directory:

    Syntax

    # ceph-osd -i <osd_id> --mkfs --mkkey --osd-uuid <uuid>

    Example

    # ceph-osd -i 0 --mkfs --mkkey --osd-uuid b367c360-b364-4b1d-8fc6-09408a9cda7a
... auth: error reading file: /var/lib/ceph/osd/ceph-0/keyring: can't open /var/lib/ceph/osd/ceph-0/keyring: (2) No such file or directory
... created new key in keyring /var/lib/ceph/osd/ceph-0/keyring

    Note

    The directory must be empty before you run ceph-osd with the --mkkey option. If you have a custom cluster name, the ceph-osd utility requires the --cluster option.

  9. As root, register the OSD authentication key. If your cluster name differs from ceph, insert your cluster name instead:

    Syntax

    # ceph auth add osd.<osd_id> osd 'allow *' mon 'allow profile osd' -i /var/lib/ceph/osd/<cluster_name>-<osd_id>/keyring

    Example

    # ceph auth add osd.0 osd 'allow *' mon 'allow profile osd' -i /var/lib/ceph/osd/ceph-0/keyring
added key for osd.0

  10. As root, add the OSD node to the CRUSH map:

    Syntax

    # ceph [--cluster <cluster_name>] osd crush add-bucket <host_name> host

    Example

    # ceph osd crush add-bucket node2 host

  11. As root, place the OSD node under the default CRUSH tree:

    Syntax

    # ceph [--cluster <cluster_name>] osd crush move <host_name> root=default

    Example

    # ceph osd crush move node2 root=default

  12. As root, add the OSD disk to the CRUSH map

    Syntax

    # ceph [--cluster <cluster_name>] osd crush add osd.<osd_id> <weight> [<bucket_type>=<bucket-name> ...]

    Example

    # ceph osd crush add osd.0 1.0 host=node2
add item id 0 name 'osd.0' weight 1 at location {host=node2} to crush map

    Note

    You can also decompile the CRUSH map, and add the OSD to the device list. Add the OSD node as a bucket, then add the device as an item in the OSD node, assign the OSD a weight, recompile the CRUSH map and set the CRUSH map. For more details, see the Editing a CRUSH map section in the Storage Strategies Guide for Red Hat Ceph Storage 3. for more details.

  13. As root, update the owner and group permissions on the newly created directory and files:

    Syntax

    # chown -R <owner>:<group> <path_to_directory>

    Example

    # chown -R ceph:ceph /var/lib/ceph/osd
# chown -R ceph:ceph /var/log/ceph
# chown -R ceph:ceph /var/run/ceph
# chown -R ceph:ceph /etc/ceph

  14. For storage clusters with custom names, as root, add the following line to the /etc/sysconfig/ceph file:

    Syntax

    # echo "CLUSTER=<custom_cluster_name>" >> /etc/sysconfig/ceph

    Example

    # echo "CLUSTER=test123" >> /etc/sysconfig/ceph

  15. The OSD node is in your Ceph storage cluster configuration. However, the OSD daemon is down and in. The new OSD must be up before it can begin receiving data. As root, enable and start the OSD process:

    Syntax

    # systemctl enable ceph-osd.target
# systemctl enable ceph-osd@<osd_id>
# systemctl start ceph-osd@<osd_id>

    Example

    # systemctl enable ceph-osd.target
# systemctl enable ceph-osd@0
# systemctl start ceph-osd@0

    Once you start the OSD daemon, it is up and in.

Now you have the monitors and some OSDs up and running. You can watch the placement groups peer by executing the following command: 

$ ceph -w

To view the OSD tree, execute the following command: 

$ ceph osd tree

Example

ID  WEIGHT    TYPE NAME        UP/DOWN  REWEIGHT  PRIMARY-AFFINITY
-1       2    root default
-2       2        host node2
 0       1            osd.0         up         1                 1
-3       1        host node3
 1       1            osd.1         up         1                 1

To expand the storage capacity by adding new OSDs to the storage cluster, see the Adding an OSD section in the Administration Guide for Red Hat Ceph Storage 3.