mirror of
https://github.com/ceph/ceph
synced 2024-12-29 23:12:27 +00:00
0376ce721a
Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>
55 lines
1.9 KiB
ReStructuredText
55 lines
1.9 KiB
ReStructuredText
.. _cephfs-multifs:
|
|
|
|
Multiple Ceph File Systems
|
|
==========================
|
|
|
|
|
|
Beginning with the Pacific release, multiple file system support is stable
|
|
and ready to use. This functionality allows configuring separate file systems
|
|
with full data separation on separate pools.
|
|
|
|
Existing clusters must set a flag to enable multiple file systems::
|
|
|
|
ceph fs flag set enable_multiple true
|
|
|
|
New Ceph clusters automatically set this.
|
|
|
|
|
|
Creating a new Ceph File System
|
|
-------------------------------
|
|
|
|
The new ``volumes`` plugin interface (see: :doc:`/cephfs/fs-volumes`) automates
|
|
most of the work of configuring a new file system. The "volume" concept is
|
|
simply a new file system. This can be done via::
|
|
|
|
ceph fs volume create <fs_name>
|
|
|
|
Ceph will create the new pools and automate the deployment of new MDS to
|
|
support the new file system. The deployment technology used, e.g. cephadm, will
|
|
also configure the MDS affinity (see: :ref:`mds-join-fs`) of new MDS daemons to
|
|
operate the new file system.
|
|
|
|
|
|
Securing access
|
|
---------------
|
|
|
|
The ``fs authorize`` command allows configuring the client's access to a
|
|
particular file system. See also in :ref:`fs-authorize-multifs`. The client will
|
|
only have visibility of authorized file systems and the Monitors/MDS will
|
|
reject access to clients without authorization.
|
|
|
|
|
|
Other Notes
|
|
-----------
|
|
|
|
Multiple file systems do not share pools. This is particularly important for
|
|
snapshots but also because no measures are in place to prevent duplicate
|
|
inodes. The Ceph commands prevent this dangerous configuration.
|
|
|
|
Each file system has its own set of MDS ranks. Consequently, each new file
|
|
system requires more MDS daemons to operate and increases operational costs.
|
|
This can be useful for increasing metadata throughput by application or user
|
|
base but also adds cost to the creation of a file system. Generally, a single
|
|
file system with subtree pinning is a better choice for isolating load between
|
|
applications.
|