From 19fcec84d8d7d21e796c7624e521b60d28ee21ed Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:45:59 +0200 Subject: Adding upstream version 16.2.11+ds. Signed-off-by: Daniel Baumann --- doc/cephfs/multifs.rst | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 doc/cephfs/multifs.rst (limited to 'doc/cephfs/multifs.rst') diff --git a/doc/cephfs/multifs.rst b/doc/cephfs/multifs.rst new file mode 100644 index 000000000..2dcba7ae0 --- /dev/null +++ b/doc/cephfs/multifs.rst @@ -0,0 +1,54 @@ +.. _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 + +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. -- cgit v1.2.3