mirror of https://github.com/ceph/ceph
78 lines
2.4 KiB
ReStructuredText
78 lines
2.4 KiB
ReStructuredText
========================
|
|
Create a Ceph filesystem
|
|
========================
|
|
|
|
Creating pools
|
|
==============
|
|
|
|
A Ceph filesystem requires at least two RADOS pools, one for data and one for metadata.
|
|
When configuring these pools, you might consider:
|
|
|
|
- Using a higher replication level for the metadata pool, as any data
|
|
loss in this pool can render the whole filesystem inaccessible.
|
|
- Using lower-latency storage such as SSDs for the metadata pool, as this
|
|
will directly affect the observed latency of filesystem operations
|
|
on clients.
|
|
|
|
Refer to :doc:`/rados/operations/pools` to learn more about managing pools. For
|
|
example, to create two pools with default settings for use with a filesystem, you
|
|
might run the following commands:
|
|
|
|
.. code:: bash
|
|
|
|
$ ceph osd pool create cephfs_data <pg_num>
|
|
$ ceph osd pool create cephfs_metadata <pg_num>
|
|
|
|
Creating a filesystem
|
|
=====================
|
|
|
|
Once the pools are created, you may enable the filesystem using the ``fs new`` command:
|
|
|
|
.. code:: bash
|
|
|
|
$ ceph fs new <fs_name> <metadata> <data>
|
|
|
|
For example:
|
|
|
|
.. code:: bash
|
|
|
|
$ ceph fs new cephfs cephfs_metadata cephfs_data
|
|
$ ceph fs ls
|
|
name: cephfs, metadata pool: cephfs_metadata, data pools: [cephfs_data ]
|
|
|
|
Once a filesystem has been created, your MDS(s) will be able to enter
|
|
an *active* state. For example, in a single MDS system:
|
|
|
|
.. code:: bash
|
|
|
|
$ ceph mds stat
|
|
e5: 1/1/1 up {0=a=up:active}
|
|
|
|
Once the filesystem is created and the MDS is active, you are ready to mount
|
|
the filesystem. If you have created more than one filesystem, you will
|
|
choose which to use when mounting.
|
|
|
|
- `Mount CephFS`_
|
|
- `Mount CephFS as FUSE`_
|
|
|
|
.. _Mount CephFS: ../../cephfs/kernel
|
|
.. _Mount CephFS as FUSE: ../../cephfs/fuse
|
|
|
|
If you have created more than one filesystem, and a client does not
|
|
specify a filesystem when mounting, you can control which filesystem
|
|
they will see by using the `ceph fs set-default` command.
|
|
|
|
Using Erasure Coded pools with CephFS
|
|
=====================================
|
|
|
|
You may use Erasure Coded pools as CephFS data pools as long as they have overwrites enabled, which is done as follows:
|
|
|
|
.. code:: bash
|
|
|
|
ceph osd pool set my_ec_pool allow_ec_overwrites true
|
|
|
|
Note that EC overwrites are only supported when using OSDS with the BlueStore backend.
|
|
|
|
You may not use Erasure Coded pools as CephFS metadata pools, because CephFS metadata is stored using RADOS *OMAP* data structures, which EC pools cannot store.
|
|
|