Chapter 3. Deployment of the Ceph File System

As a storage administrator, you can deploy Ceph File Systems (CephFS) in a storage environment and have clients mount those Ceph File Systems to meet the storage needs.

Basically, the deployment workflow is three steps:

Create Ceph File Systems on a Ceph Monitor node.
Create a Ceph client user with the appropriate capabilities, and make the client key available on the node where the Ceph File System will be mounted.
Mount CephFS on a dedicated node, using either a kernel client or a File System in User Space (FUSE) client.

Prerequisites

A running, and healthy Red Hat Ceph Storage cluster.
Installation and configuration of the Ceph Metadata Server daemon (ceph-mds).

3.1. Layout, quota, snapshot, and network restrictions

These user capabilities can help you restrict access to a Ceph File System (CephFS) based on the needed requirements.

Important

All user capability flags, except rw, must be specified in alphabetical order.

Layouts and Quotas

When using layouts or quotas, clients require the p flag, in addition to rw capabilities. Setting the p flag restricts all the attributes being set by special extended attributes, those with a ceph. prefix. Also, this restricts other means of setting these fields, such as openc operations with layouts.

Example

client.0
    key: AQAz7EVWygILFRAAdIcuJ10opU/JKyfFmxhuaw==
    caps: [mds] allow rwp
    caps: [mon] allow r
    caps: [osd] allow rw tag cephfs data=cephfs_a

client.1
    key: AQAz7EVWygILFRAAdIcuJ11opU/JKyfFmxhuaw==
    caps: [mds] allow rw
    caps: [mon] allow r
    caps: [osd] allow rw tag cephfs data=cephfs_a

In this example, client.0 can modify layouts and quotas on the file system cephfs_a, but client.1 cannot.

Snapshots

When creating or deleting snapshots, clients require the s flag, in addition to rw capabilities. When the capability string also contains the p flag, the s flag must appear after it.

Example

client.0
    key: AQAz7EVWygILFRAAdIcuJ10opU/JKyfFmxhuaw==
    caps: [mds] allow rw, allow rws path=/temp
    caps: [mon] allow r
    caps: [osd] allow rw tag cephfs data=cephfs_a

In this example, client.0 can create or delete snapshots in the temp directory of file system cephfs_a.

Network

Restricting clients connecting from a particular network.

Example

client.0
  key: AQAz7EVWygILFRAAdIcuJ10opU/JKyfFmxhuaw==
  caps: [mds] allow r network 10.0.0.0/8, allow rw path=/bar network 10.0.0.0/8
  caps: [mon] allow r network 10.0.0.0/8
  caps: [osd] allow rw tag cephfs data=cephfs_a network 10.0.0.0/8

The optional network and prefix length is in CIDR notation, for example, 10.3.0.0/16.

Additional Resources

See the Creating client users for a Ceph File System section in the Red Hat Ceph Storage File System Guide for details on setting the Ceph user capabilities.

3.2. Creating Ceph File Systems

You can create multiple Ceph File Systems (CephFS) on a Ceph Monitor node.

Prerequisites

A running, and healthy Red Hat Ceph Storage cluster.
Installation and configuration of the Ceph Metadata Server daemon (ceph-mds).
Root-level access to a Ceph Monitor node.
Root-level access to a Ceph client node.

Procedure

Configure the client node to use the Ceph storage cluster.
1. Enable the Red Hat Ceph Storage Tools repository:
  Red Hat Enterprise Linux 8
```
[root@client01 ~]# subscription-manager repos --enable=rhceph-6-tools-for-rhel-8-x86_64-rpms
```
  Red Hat Enterprise Linux 9
```
[root@client01 ~]# subscription-manager repos --enable=rhceph-6-tools-for-rhel-9-x86_64-rpms
```
2. Install the ceph-fuse package:
```
[root@client ~]# dnf install ceph-fuse
```
3. Copy the Ceph client keyring from the Ceph Monitor node to the client node:
  Syntax
```
scp root@MONITOR_NODE_NAME:/etc/ceph/KEYRING_FILE /etc/ceph/
```
  Replace MONITOR_NODE_NAME with the Ceph Monitor host name or IP address.
  Example
```
[root@client ~]# scp root@192.168.0.1:/etc/ceph/ceph.client.1.keyring /etc/ceph/
```
4. Copy the Ceph configuration file from a Ceph Monitor node to the client node:
  Syntax
```
scp root@MONITOR_NODE_NAME:/etc/ceph/ceph.conf /etc/ceph/ceph.conf
```
  Replace MONITOR_NODE_NAME with the Ceph Monitor host name or IP address.
  Example
```
[root@client ~]# scp root@192.168.0.1:/etc/ceph/ceph.conf /etc/ceph/ceph.conf
```
5. Set the appropriate permissions for the configuration file:
```
[root@client ~]# chmod 644 /etc/ceph/ceph.conf
```
Create a Ceph File System:
Syntax
```
ceph fs volume create FILE_SYSTEM_NAME
```
Example
```
[root@mon ~]# ceph fs volume create cephfs01
```
Repeat this step to create additional file systems.
Note
By running this command, Ceph automatically creates the new pools, and deploys a new Ceph Metadata Server (MDS) daemon to support the new file system. This also configures the MDS affinity accordingly.

Verify access to the new Ceph File System from a Ceph client.

Authorize a Ceph client to access the new file system:

Syntax

ceph fs authorize FILE_SYSTEM_NAME CLIENT_NAME DIRECTORY PERMISSIONS

Example

[root@mon ~]# ceph fs authorize cephfs01 client.1 / rw
[client.1]
    key = BQAmthpf81M+JhAAiHDYQkMiCq3x+J0n9e8REK==

[root@mon ~]# ceph auth get client.1
exported keyring for client.1
[client.1]
    key = BQAmthpf81M+JhAAiHDYQkMiCq3x+J0n9e8REK==
    caps mds = "allow rw fsname=cephfs01"
    caps mon = "allow r fsname=cephfs01"
    caps osd = "allow rw tag cephfs data=cephfs01"

Note

Optionally, you can add a safety measure by specifying the root_squash option. This prevents accidental deletion scenarios by disallowing clients with a uid=0 or gid=0 to do write operations, but still allows read operations.

Example

[root@mon ~]# ceph fs authorize cephfs01 client.1 / rw root_squash /volumes rw
[client.1]
    key = BQAmthpf81M+JhAAiHDYQkMiCq3x+J0n9e8REK==

[root@mon ~]# ceph auth get client.1
[client.1]
    key = BQAmthpf81M+JhAAiHDYQkMiCq3x+J0n9e8REK==
    caps mds = "allow rw fsname=cephfs01 root_squash, allow rw fsname=cephfs01 path=/volumes"
    caps mon = "allow r fsname=cephfs01"
    caps osd = "allow rw tag cephfs data=cephfs01"

In this example, root_squash is enabled for the file system cephfs01, except within the /volumes directory tree.

Important

The Ceph client can only see the CephFS it is authorized for.

Copy the Ceph user’s keyring to the Ceph client node:

Syntax

ceph auth get CLIENT_NAME > OUTPUT_FILE_NAME
scp OUTPUT_FILE_NAME TARGET_NODE_NAME:/etc/ceph

Example

[root@mon ~]# ceph auth get client.1 > ceph.client.1.keyring
exported keyring for client.1
[root@mon ~]# scp ceph.client.1.keyring client:/etc/ceph
root@client's password:
ceph.client.1.keyring                     100%  178   333.0KB/s   00:00

On the Ceph client node, create a new directory:

Syntax

mkdir PATH_TO_NEW_DIRECTORY_NAME

Example

[root@client ~]# mkdir /mnt/mycephfs

On the Ceph client node, mount the new Ceph File System:

Syntax

ceph-fuse PATH_TO_NEW_DIRECTORY_NAME -n CEPH_USER_NAME --client-fs=_FILE_SYSTEM_NAME

Example

[root@client ~]# ceph-fuse /mnt/mycephfs/ -n client.1 --client-fs=cephfs01
ceph-fuse[555001]: starting ceph client
2022-05-09T07:33:27.158+0000 7f11feb81200 -1 init, newargv = 0x55fc4269d5d0 newargc=15
ceph-fuse[555001]: starting fuse

On the Ceph client node, list the directory contents of the new mount point, or create a file on the new mount point.

Additional Resources

See the Creating client users for a Ceph File System section in the Red Hat Ceph Storage File System Guide for more details.
See the Mounting the Ceph File System as a kernel client section in the Red Hat Ceph Storage File System Guide for more details.
See the Mounting the Ceph File System as a FUSE client section in the Red Hat Ceph Storage File System Guide for more details.
See Ceph File System limitations and the POSIX standards section in the Red Hat Ceph Storage File System Guide for more details.
See the Pools chapter in the Red Hat Ceph Storage Storage Strategies Guide for more details.

3.3. Adding an erasure-coded pool to a Ceph File System

By default, Ceph uses replicated pools for data pools. You can also add an additional erasure-coded data pool to the Ceph File System, if needed. Ceph File Systems (CephFS) backed by erasure-coded pools use less overall storage compared to Ceph File Systems backed by replicated pools. While erasure-coded pools use less overall storage, they also use more memory and processor resources than replicated pools.

Important

CephFS EC pools are for archival purpose only.

Important

For production environments, Red Hat recommends using the default replicated data pool for CephFS. The creation of inodes in CephFS creates at least one object in the default data pool. It is better to use a replicated pool for the default data to improve small-object write performance, and to improve read performance for updating backtraces.

Prerequisites

A running Red Hat Ceph Storage cluster.
An existing Ceph File System.
Pools using BlueStore OSDs.
Root-level access to a Ceph Monitor node.
Installation of the attr package.

Procedure

Create an erasure-coded data pool for CephFS:

Syntax

ceph osd pool create DATA_POOL_NAME erasure

Example

[root@mon ~]# ceph osd pool create cephfs-data-ec01 erasure
pool 'cephfs-data-ec01' created

Verify the pool was added:
Example
```
[root@mon ~]# ceph osd lspools
```

Enable overwrites on the erasure-coded pool:

Syntax

ceph osd pool set DATA_POOL_NAME allow_ec_overwrites true

Example

[root@mon ~]# ceph osd pool set cephfs-data-ec01 allow_ec_overwrites true
set pool 15 allow_ec_overwrites to true

Verify the status of the Ceph File System:

Syntax

ceph fs status FILE_SYSTEM_NAME

Example

[root@mon ~]# ceph fs status cephfs-ec
cephfs-ec - 14 clients
=========
RANK  STATE              MDS                ACTIVITY     DNS    INOS   DIRS   CAPS
 0    active  cephfs-ec.example.ooymyq  Reqs:    0 /s  8231   8233    891    921
       POOL           TYPE     USED  AVAIL
cephfs-metadata-ec  metadata   787M  8274G
  cephfs-data-ec      data    2360G  12.1T

       STANDBY MDS
cephfs-ec.example.irsrql
cephfs-ec.example.cauuaj

Add the erasure-coded data pool to the existing CephFS:
Syntax
```
ceph fs add_data_pool FILE_SYSTEM_NAME DATA_POOL_NAME
```
Example
```
[root@mon ~]# ceph fs add_data_pool cephfs-ec cephfs-data-ec01
```
This example adds the new data pool, cephfs-data-ec01, to the existing erasure-coded file system, cephfs-ec.

Verify that the erasure-coded pool was added to the Ceph File System:

Syntax

ceph fs status FILE_SYSTEM_NAME

Example

[root@mon ~]# ceph fs status cephfs-ec
cephfs-ec - 14 clients
=========
RANK  STATE              MDS                ACTIVITY     DNS    INOS   DIRS   CAPS
 0    active  cephfs-ec.example.ooymyq  Reqs:    0 /s  8231   8233    891    921
       POOL           TYPE     USED  AVAIL
cephfs-metadata-ec  metadata   787M  8274G
  cephfs-data-ec      data    2360G  12.1T
 cephfs-data-ec01     data       0   12.1T

       STANDBY MDS
cephfs-ec.example.irsrql
cephfs-ec.example.cauuaj

Set the file layout on a new directory:

Syntax

mkdir PATH_TO_DIRECTORY
setfattr -n ceph.dir.layout.pool -v DATA_POOL_NAME PATH_TO_DIRECTORY

Example

[root@mon ~]# mkdir /mnt/cephfs/newdir
[root@mon ~]# setfattr -n ceph.dir.layout.pool -v cephfs-data-ec01 /mnt/cephfs/newdir

In this example, all new files created in the /mnt/cephfs/newdir directory inherit the directory layout and places the data in the newly added erasure-coded pool.

Additional Resources

See The Ceph File System Metadata Server chapter in the Red Hat Ceph Storage File System Guide for more information about CephFS MDS.
See the Creating Ceph File Systems section in the Red Hat Ceph Storage File System Guide for more information.
See the Erasure Code Pools chapter in the Red Hat Ceph Storage Storage Strategies Guide for more information.
See the Erasure Coding with Overwrites section in the Red Hat Ceph Storage Storage Strategies Guide for more information.

3.4. Creating client users for a Ceph File System

Red Hat Ceph Storage uses cephx for authentication, which is enabled by default. To use cephx with the Ceph File System, create a user with the correct authorization capabilities on a Ceph Monitor node and make its key available on the node where the Ceph File System will be mounted.

Prerequisites

A running Red Hat Ceph Storage cluster.
Installation and configuration of the Ceph Metadata Server daemon (ceph-mds).
Root-level access to a Ceph Monitor node.
Root-level access to a Ceph client node.

Procedure

Log into the Cephadm shell on the monitor node:
Example
```
[root@host01 ~]# cephadm shell
```
On a Ceph Monitor node, create a client user:
Syntax
```
ceph fs authorize FILE_SYSTEM_NAME client.CLIENT_NAME /DIRECTORY CAPABILITY [/DIRECTORY CAPABILITY] PERMISSIONS ...
```
- To restrict the client to only writing in the temp directory of filesystem cephfs_a:
  Example
```
[ceph: root@host01 /]# ceph fs authorize cephfs_a client.1 / r /temp rw

client.1
  key = AQBSdFhcGZFUDRAAcKhG9Cl2HPiDMMRv4DC43A==
```
- To completely restrict the client to the temp directory, remove the root (/) directory:
  Example
```
[ceph: root@host01 /]# ceph fs authorize cephfs_a client.1 /temp rw
```
Note
Supplying all or asterisk as the file system name grants access to every file system. Typically, it is necessary to quote the asterisk to protect it from the shell.

Verify the created key:

Syntax

ceph auth get client.ID

Example

[ceph: root@host01 /]# ceph auth get client.1

client.1
  key = AQBSdFhcGZFUDRAAcKhG9Cl2HPiDMMRv4DC43A==
  caps mds = "allow r, allow rw path=/temp"
  caps mon = "allow r"
  caps osd = "allow rw tag cephfs data=cephfs_a"

Copy the keyring to the client.

On the Ceph Monitor node, export the keyring to a file:

Syntax

ceph auth get client.ID -o ceph.client.ID.keyring

Example

[ceph: root@host01 /]# ceph auth get client.1 -o ceph.client.1.keyring
exported keyring for client.1

Copy the client keyring from the Ceph Monitor node to the /etc/ceph/ directory on the client node:

Syntax

scp /ceph.client.ID.keyring root@CLIENT_NODE_NAME:/etc/ceph/ceph.client.ID.keyring

Replace CLIENT_NODE_NAME with the Ceph client node name or IP.

Example

[ceph: root@host01 /]# scp /ceph.client.1.keyring root@client01:/etc/ceph/ceph.client.1.keyring

From the client node, set the appropriate permissions for the keyring file:

Syntax

chmod 644 ceph.client.ID.keyring

Example

[root@client01 ~]# chmod 644 /etc/ceph/ceph.client.1.keyring

Additional Resources

See the Ceph user management chapter in the Red Hat Ceph Storage Administration Guide for more details.

3.5. Mounting the Ceph File System as a kernel client

You can mount the Ceph File System (CephFS) as a kernel client, either manually or automatically on system boot.

Important

Clients running on other Linux distributions, aside from Red Hat Enterprise Linux, are permitted but not supported. If issues are found in the CephFS Metadata Server or other parts of the storage cluster when using these clients, Red Hat will address them. If the cause is found to be on the client side, then the issue will have to be addressed by the kernel vendor of the Linux distribution.

Prerequisites

Root-level access to a Linux-based client node.
Root-level access to a Ceph Monitor node.
An existing Ceph File System.

Procedure

Configure the client node to use the Ceph storage cluster.
1. Enable the Red Hat Ceph Storage 7 Tools repository:
  Red Hat Enterprise Linux 9
```
[root@client01 ~]# subscription-manager repos --enable=rhceph-6-tools-for-rhel-9-x86_64-rpms
```
2. Install the ceph-common package:
```
[root@client01 ~]# dnf install ceph-common
```
3. Log into the Cephadm shell on the monitor node:
  Example
```
[root@host01 ~]# cephadm shell
```
4. Copy the Ceph client keyring from the Ceph Monitor node to the client node:
  Syntax
```
scp /ceph.client.ID.keyring root@CLIENT_NODE_NAME:/etc/ceph/ceph.client.ID.keyring
```
  Replace CLIENT_NODE_NAME with the Ceph client host name or IP address.
  Example
```
[ceph: root@host01 /]# scp /ceph.client.1.keyring root@client01:/etc/ceph/ceph.client.1.keyring
```
5. Copy the Ceph configuration file from a Ceph Monitor node to the client node:
  Syntax
```
scp /etc/ceph/ceph.conf root@CLIENT_NODE_NAME:/etc/ceph/ceph.conf
```
  Replace CLIENT_NODE_NAME with the Ceph client host name or IP address.
  Example
```
[ceph: root@host01 /]# scp /etc/ceph/ceph.conf root@client01:/etc/ceph/ceph.conf
```
6. From the client node, set the appropriate permissions for the configuration file:
```
[root@client01 ~]# chmod 644 /etc/ceph/ceph.conf
```
7. Choose either automatically or manually mounting.

Manually Mounting

Create a mount directory on the client node:

Syntax

mkdir -p MOUNT_POINT

Example

[root@client01 ~]# mkdir -p /mnt/cephfs

Mount the Ceph File System. To specify multiple Ceph Monitor addresses, separate them with commas in the mount command, specify the mount point, and set the client name:
Note
As of Red Hat Ceph Storage 4.1, mount.ceph can read keyring files directly. As such, a secret file is no longer necessary. Just specify the client ID with name=CLIENT_ID, and mount.ceph will find the right keyring file.
Syntax
```
mount -t ceph MONITOR-1_NAME:6789,MONITOR-2_NAME:6789,MONITOR-3_NAME:6789:/ MOUNT_POINT -o name=CLIENT_ID,fs=FILE_SYSTEM_NAME
```
Example
```
[root@client01 ~]# mount -t ceph mon1:6789,mon2:6789,mon3:6789:/ /mnt/cephfs -o name=1,fs=cephfs01
```
Note
You can configure a DNS server so that a single host name resolves to multiple IP addresses. Then you can use that single host name with the mount command, instead of supplying a comma-separated list.
Note
You can also replace the Monitor host names with the string :/ and mount.ceph will read the Ceph configuration file to determine which Monitors to connect to.
Note
You can set the nowsync option to asynchronously execute file creation and removal on the Red Hat Ceph Storage clusters. This improves the performance of some workloads by avoiding round-trip latency for these system calls without impacting consistency. The nowsync option requires kernel clients with Red Hat Enterprise Linux 9.0 or later.
Example
```
[root@client01 ~]# mount -t ceph mon1:6789,mon2:6789,mon3:6789:/ /mnt/cephfs -o nowsync,name=1,fs=cephfs01
```
Verify that the file system is successfully mounted:
Syntax
```
stat -f MOUNT_POINT
```
Example
```
[root@client01 ~]# stat -f /mnt/cephfs
```

Automatically Mounting

On the client host, create a new directory for mounting the Ceph File System.
Syntax
```
mkdir -p MOUNT_POINT
```
Example
```
[root@client01 ~]# mkdir -p /mnt/cephfs
```
Edit the /etc/fstab file as follows:
Syntax
```
#DEVICE                                              PATH                      TYPE               OPTIONS
MON_0_HOST:PORT,            MOUNT_POINT          ceph         name=CLIENT_ID,
MON_1_HOST:PORT,                                                         ceph.client_mountpoint=/VOL/SUB_VOL_GROUP/SUB_VOL/UID_SUB_VOL,                                                       fs=FILE_SYSTEM_NAME,
MON_2_HOST:PORT:/q[_VOL_]/SUB_VOL/UID_SUB_VOL,            [ADDITIONAL_OPTIONS]
```
The first column sets the Ceph Monitor host names and the port number.
The second column sets the mount point
The third column sets the file system type, in this case, ceph, for CephFS.
The fourth column sets the various options, such as, the user name and the secret file using the name and secretfile options. You can also set specific volumes, sub-volume groups, and sub-volumes using the ceph.client_mountpoint option.
Set the _netdev option to ensure that the file system is mounted after the networking subsystem starts to prevent hanging and networking issues. If you do not need access time information, then setting the noatime option can increase performance.
Set the fifth and sixth columns to zero.
Example
```
#DEVICE         PATH                   TYPE    OPTIONS         DUMP  FSCK
mon1:6789,      /mnt/cephfs            ceph    name=1,            0     0
mon2:6789,                                     ceph.client_mountpoint=/my_vol/my_sub_vol_group/my_sub_vol/0,
mon3:6789:/                                    fs=cephfs01,
                                               _netdev,noatime
```
The Ceph File System will be mounted on the next system boot.
Note
As of Red Hat Ceph Storage 4.1, mount.ceph can read keyring files directly. As such, a secret file is no longer necessary. Just specify the client ID with name=CLIENT_ID, and mount.ceph will find the right keyring file.
Note
You can also replace the Monitor host names with the string :/ and mount.ceph will read the Ceph configuration file to determine which Monitors to connect to.

Additional Resources

See the mount(8) manual page.
See the Ceph user management chapter in the Red Hat Ceph Storage Administration Guide for more details on creating a Ceph user.
See the Creating Ceph File Systems section of the Red Hat Ceph Storage File System Guide for details.

3.6. Mounting the Ceph File System as a FUSE client

You can mount the Ceph File System (CephFS) as a File System in User Space (FUSE) client, either manually or automatically on system boot.

Prerequisites

Root-level access to a Linux-based client node.
Root-level access to a Ceph Monitor node.
An existing Ceph File System.

Procedure

Configure the client node to use the Ceph storage cluster.
1. Enable the Red Hat Ceph Storage 7 Tools repository:
  Red Hat Enterprise Linux 8
```
[root@client01 ~]# subscription-manager repos --enable=6-tools-for-rhel-8-x86_64-rpms
```
  Red Hat Enterprise Linux 9
```
[root@client01 ~]# subscription-manager repos --enable=6-tools-for-rhel-9-x86_64-rpms
```
2. Install the ceph-fuse package:
```
[root@client01 ~]# dnf install ceph-fuse
```
3. Log into the Cephadm shell on the monitor node:
  Example
```
[root@host01 ~]# cephadm shell
```
4. Copy the Ceph client keyring from the Ceph Monitor node to the client node:
  Syntax
```
scp /ceph.client.ID.keyring root@CLIENT_NODE_NAME:/etc/ceph/ceph.client.ID.keyring
```
  Replace CLIENT_NODE_NAME with the Ceph client host name or IP address.
  Example
```
[ceph: root@host01 /]# scp /ceph.client.1.keyring root@client01:/etc/ceph/ceph.client.1.keyring
```
5. Copy the Ceph configuration file from a Ceph Monitor node to the client node:
  Syntax
```
scp /etc/ceph/ceph.conf root@CLIENT_NODE_NAME:/etc/ceph/ceph.conf
```
  Replace CLIENT_NODE_NAME with the Ceph client host name or IP address.
  Example
```
[ceph: root@host01 /]# scp /etc/ceph/ceph.conf root@client01:/etc/ceph/ceph.conf
```
6. From the client node, set the appropriate permissions for the configuration file:
```
[root@client01 ~]# chmod 644 /etc/ceph/ceph.conf
```
7. Choose either automatically or manually mounting.

Manually Mounting

On the client node, create a directory for the mount point:
Syntax
```
mkdir PATH_TO_MOUNT_POINT
```
Example
```
[root@client01 ~]# mkdir /mnt/mycephfs
```
Note
If you used the path option with MDS capabilities, then the mount point must be within what is specified by the path.
Use the ceph-fuse utility to mount the Ceph File System.
Syntax
```
ceph-fuse -n client.CLIENT_ID --client_fs FILE_SYSTEM_NAME MOUNT_POINT
```
Example
```
[root@client01 ~]# ceph-fuse -n client.1 --client_fs cephfs01 /mnt/mycephfs
```
Note
If you do not use the default name and location of the user keyring, that is /etc/ceph/ceph.client.CLIENT_ID.keyring, then use the --keyring option to specify the path to the user keyring, for example:
Example
```
[root@client01 ~]# ceph-fuse -n client.1 --keyring=/etc/ceph/client.1.keyring /mnt/mycephfs
```
Note
Use the -r option to instruct the client to treat that path as its root:
Syntax
```
ceph-fuse -n client.CLIENT_ID MOUNT_POINT -r PATH
```
Example
```
[root@client01 ~]# ceph-fuse -n client.1 /mnt/cephfs -r /home/cephfs
```
Note
If you want to automatically reconnect an evicted Ceph client, then add the --client_reconnect_stale=true option.
Example
```
[root@client01 ~]# ceph-fuse -n client.1 /mnt/cephfs --client_reconnect_stale=true
```
Verify that the file system is successfully mounted:
Syntax
```
stat -f MOUNT_POINT
```
Example
```
[root@client01 ~]# stat -f /mnt/cephfs
```

Automatically Mounting

On the client node, create a directory for the mount point:
Syntax
```
mkdir PATH_TO_MOUNT_POINT
```
Example
```
[root@client01 ~]# mkdir /mnt/mycephfs
```
Note
If you used the path option with MDS capabilities, then the mount point must be within what is specified by the path.
Edit the /etc/fstab file as follows:
Syntax
```
#DEVICE                 PATH           TYPE          OPTIONS                  DUMP  FSCK
HOST_NAME:PORT,     MOUNT_POINT fuse.ceph     ceph.id=CLIENT_ID,        0     0
HOST_NAME:PORT,                                  ceph.client_mountpoint=/VOL/SUB_VOL_GROUP/SUB_VOL/UID_SUB_VOL,
HOST_NAME:PORT:/                                 ceph.client_fs=FILE_SYSTEM_NAME,ceph.name=USERNAME,ceph.keyring=/etc/ceph/KEYRING_FILE,
                                                     [ADDITIONAL_OPTIONS]
```
The first column sets the Ceph Monitor host names and the port number.
The second column sets the mount point
The third column sets the file system type, in this case, fuse.ceph, for CephFS.
The fourth column sets the various options, such as the user name and the keyring using the ceph.name and ceph.keyring options. You can also set specific volumes, sub-volume groups, and sub-volumes using the ceph.client_mountpoint option. To specify which Ceph File System to access, use the ceph.client_fs option. Set the _netdev option to ensure that the file system is mounted after the networking subsystem starts to prevent hanging and networking issues. If you do not need access time information, then setting the noatime option can increase performance. If you want to automatically reconnect after an eviction, then set the client_reconnect_stale=true option.
Set the fifth and sixth columns to zero.
Example
```
#DEVICE         PATH              TYPE         OPTIONS         DUMP  FSCK
mon1:6789,      /mnt/mycephfs       fuse.ceph    ceph.id=1,         0     0
mon2:6789,                                     ceph.client_mountpoint=/my_vol/my_sub_vol_group/my_sub_vol/0,
mon3:6789:/                                    ceph.client_fs=cephfs01,ceph.name=client.1,ceph.keyring=/etc/ceph/client1.keyring,
                                               _netdev,defaults
```
The Ceph File System will be mounted on the next system boot.

Additional Resources

The ceph-fuse(8) manual page.
See the Ceph user management chapter in the Red Hat Ceph Storage Administration Guide for more details on creating a Ceph user.
See the Creating Ceph File Systems section of the Red Hat Ceph Storage File System Guide for details.

Additional Resources

See Section 2.5, “Management of MDS service using the Ceph Orchestrator” to install Ceph Metadata servers.
See Section 3.2, “Creating Ceph File Systems” for details.
See Section 3.4, “Creating client users for a Ceph File System” for details.
See Section 3.5, “Mounting the Ceph File System as a kernel client” for details.
See Section 3.6, “Mounting the Ceph File System as a FUSE client” for details.
See Chapter 2, The Ceph File System Metadata Server for details on configuring the CephFS Metadata Server daemon.

Chapter 3. Deployment of the Ceph File System

3.1. Layout, quota, snapshot, and network restrictions

3.2. Creating Ceph File Systems

3.3. Adding an erasure-coded pool to a Ceph File System

3.4. Creating client users for a Ceph File System

3.5. Mounting the Ceph File System as a kernel client

3.6. Mounting the Ceph File System as a FUSE client

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