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9f95a23c | 1 | .. _ceph-file-system: |
91327a77 | 2 | |
7c673cae | 3 | ================= |
9f95a23c | 4 | Ceph File System |
7c673cae FG |
5 | ================= |
6 | ||
9f95a23c TL |
7 | The Ceph File System, or **CephFS**, is a POSIX-compliant file system built on |
8 | top of Ceph's distributed object store, **RADOS**. CephFS endeavors to provide | |
9 | a state-of-the-art, multi-use, highly available, and performant file store for | |
10 | a variety of applications, including traditional use-cases like shared home | |
11 | directories, HPC scratch space, and distributed workflow shared storage. | |
7c673cae | 12 | |
9f95a23c TL |
13 | CephFS achieves these goals through the use of some novel architectural |
14 | choices. Notably, file metadata is stored in a separate RADOS pool from file | |
15 | data and served via a resizable cluster of *Metadata Servers*, or **MDS**, | |
16 | which may scale to support higher throughput metadata workloads. Clients of | |
17 | the file system have direct access to RADOS for reading and writing file data | |
18 | blocks. For this reason, workloads may linearly scale with the size of the | |
19 | underlying RADOS object store; that is, there is no gateway or broker mediating | |
20 | data I/O for clients. | |
7c673cae | 21 | |
9f95a23c TL |
22 | Access to data is coordinated through the cluster of MDS which serve as |
23 | authorities for the state of the distributed metadata cache cooperatively | |
24 | maintained by clients and MDS. Mutations to metadata are aggregated by each MDS | |
25 | into a series of efficient writes to a journal on RADOS; no metadata state is | |
26 | stored locally by the MDS. This model allows for coherent and rapid | |
27 | collaboration between clients within the context of a POSIX file system. | |
7c673cae | 28 | |
9f95a23c | 29 | .. image:: cephfs-architecture.svg |
7c673cae | 30 | |
9f95a23c TL |
31 | CephFS is the subject of numerous academic papers for its novel designs and |
32 | contributions to file system research. It is the oldest storage interface in | |
33 | Ceph and was once the primary use-case for RADOS. Now it is joined by two | |
34 | other storage interfaces to form a modern unified storage system: RBD (Ceph | |
35 | Block Devices) and RGW (Ceph Object Storage Gateway). | |
7c673cae | 36 | |
7c673cae | 37 | |
9f95a23c TL |
38 | Getting Started with CephFS |
39 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
7c673cae | 40 | |
9f95a23c TL |
41 | For most deployments of Ceph, setting up a CephFS file system is as simple as: |
42 | ||
43 | .. code:: bash | |
44 | ||
45 | ceph fs volume create <fs name> | |
46 | ||
47 | The Ceph `Orchestrator`_ will automatically create and configure MDS for | |
48 | your file system if the back-end deployment technology supports it (see | |
49 | `Orchestrator deployment table`_). Otherwise, please `deploy MDS manually | |
50 | as needed`_. | |
51 | ||
52 | Finally, to mount CephFS on your client nodes, see `Mount CephFS: | |
53 | Prerequisites`_ page. Additionally, a command-line shell utility is available | |
54 | for interactive access or scripting via the `cephfs-shell`_. | |
55 | ||
56 | .. _Orchestrator: ../mgr/orchestrator | |
57 | .. _deploy MDS manually as needed: add-remove-mds | |
58 | .. _Orchestrator deployment table: ../mgr/orchestrator/#current-implementation-status | |
59 | .. _Mount CephFS\: Prerequisites: mount-prerequisites | |
60 | .. _cephfs-shell: cephfs-shell | |
7c673cae FG |
61 | |
62 | ||
63 | .. raw:: html | |
64 | ||
9f95a23c | 65 | <!--- |
7c673cae | 66 | |
9f95a23c TL |
67 | Administration |
68 | ^^^^^^^^^^^^^^ | |
7c673cae | 69 | |
9f95a23c TL |
70 | .. raw:: html |
71 | ||
72 | ---> | |
7c673cae FG |
73 | |
74 | .. toctree:: | |
9f95a23c TL |
75 | :maxdepth: 1 |
76 | :hidden: | |
7c673cae | 77 | |
9f95a23c TL |
78 | Create a CephFS file system <createfs> |
79 | Administrative commands <administration> | |
f67539c2 TL |
80 | Creating Multiple File Systems <multifs> |
81 | Provision/Add/Remove MDS(s) <add-remove-mds> | |
9f95a23c | 82 | MDS failover and standby configuration <standby> |
adb31ebb | 83 | MDS Cache Configuration <cache-configuration> |
9f95a23c TL |
84 | MDS Configuration Settings <mds-config-ref> |
85 | Manual: ceph-mds <../../man/8/ceph-mds> | |
86 | Export over NFS <nfs> | |
f6b5b4d7 | 87 | Export over NFS with volume nfs interface <fs-nfs-exports> |
9f95a23c TL |
88 | Application best practices <app-best-practices> |
89 | FS volume and subvolumes <fs-volumes> | |
90 | CephFS Quotas <quota> | |
91 | Health messages <health-messages> | |
92 | Upgrading old file systems <upgrading> | |
f67539c2 TL |
93 | CephFS Top Utility <cephfs-top> |
94 | Scheduled Snapshots <snap-schedule> | |
b3b6e05e | 95 | CephFS Snapshot Mirroring <cephfs-mirroring> |
7c673cae | 96 | |
9f95a23c | 97 | .. raw:: html |
7c673cae | 98 | |
9f95a23c | 99 | <!--- |
7c673cae | 100 | |
9f95a23c TL |
101 | Mounting CephFS |
102 | ^^^^^^^^^^^^^^^ | |
103 | ||
104 | .. raw:: html | |
105 | ||
106 | ---> | |
7c673cae FG |
107 | |
108 | .. toctree:: | |
9f95a23c TL |
109 | :maxdepth: 1 |
110 | :hidden: | |
111 | ||
112 | Client Configuration Settings <client-config-ref> | |
113 | Client Authentication <client-auth> | |
114 | Mount CephFS: Prerequisites <mount-prerequisites> | |
115 | Mount CephFS using Kernel Driver <mount-using-kernel-driver> | |
116 | Mount CephFS using FUSE <mount-using-fuse> | |
f67539c2 | 117 | Mount CephFS on Windows <ceph-dokan> |
9f95a23c TL |
118 | Use the CephFS Shell <cephfs-shell> |
119 | Supported Features of Kernel Driver <kernel-features> | |
120 | Manual: ceph-fuse <../../man/8/ceph-fuse> | |
121 | Manual: mount.ceph <../../man/8/mount.ceph> | |
122 | Manual: mount.fuse.ceph <../../man/8/mount.fuse.ceph> | |
7c673cae | 123 | |
7c673cae | 124 | |
9f95a23c TL |
125 | .. raw:: html |
126 | ||
127 | <!--- | |
7c673cae | 128 | |
9f95a23c TL |
129 | CephFS Concepts |
130 | ^^^^^^^^^^^^^^^ | |
131 | ||
132 | .. raw:: html | |
7c673cae | 133 | |
9f95a23c | 134 | ---> |
7c673cae FG |
135 | |
136 | .. toctree:: | |
9f95a23c TL |
137 | :maxdepth: 1 |
138 | :hidden: | |
7c673cae | 139 | |
11fdf7f2 | 140 | MDS States <mds-states> |
7c673cae | 141 | POSIX compatibility <posix> |
9f95a23c | 142 | MDS Journaling <mds-journaling> |
7c673cae | 143 | File layouts <file-layouts> |
9f95a23c TL |
144 | Distributed Metadata Cache <mdcache> |
145 | Dynamic Metadata Management in CephFS <dynamic-metadata-management> | |
146 | CephFS IO Path <cephfs-io-path> | |
81eedcae | 147 | LazyIO <lazyio> |
9f95a23c TL |
148 | Directory fragmentation <dirfrags> |
149 | Multiple active MDS daemons <multimds> | |
150 | ||
151 | ||
152 | .. raw:: html | |
153 | ||
154 | <!--- | |
155 | ||
156 | Troubleshooting and Disaster Recovery | |
157 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | |
158 | ||
159 | .. raw:: html | |
160 | ||
161 | ---> | |
11fdf7f2 TL |
162 | |
163 | .. toctree:: | |
164 | :hidden: | |
165 | ||
9f95a23c TL |
166 | Client eviction <eviction> |
167 | Scrubbing the File System <scrub> | |
168 | Handling full file systems <full> | |
169 | Metadata repair <disaster-recovery-experts> | |
170 | Troubleshooting <troubleshooting> | |
171 | Disaster recovery <disaster-recovery> | |
172 | cephfs-journal-tool <cephfs-journal-tool> | |
173 | ||
7c673cae FG |
174 | |
175 | .. raw:: html | |
176 | ||
9f95a23c TL |
177 | <!--- |
178 | ||
179 | Developer Guides | |
180 | ^^^^^^^^^^^^^^^^ | |
181 | ||
182 | .. raw:: html | |
7c673cae | 183 | |
9f95a23c | 184 | ---> |
7c673cae FG |
185 | |
186 | .. toctree:: | |
9f95a23c TL |
187 | :maxdepth: 1 |
188 | :hidden: | |
7c673cae | 189 | |
9f95a23c | 190 | Journaler Configuration <journaler> |
7c673cae | 191 | Client's Capabilities <capabilities> |
f67539c2 | 192 | Java and Python bindings <api/index> |
7c673cae FG |
193 | Mantle <mantle> |
194 | ||
9f95a23c TL |
195 | |
196 | .. raw:: html | |
197 | ||
198 | <!--- | |
199 | ||
200 | Additional Details | |
201 | ^^^^^^^^^^^^^^^^^^ | |
202 | ||
203 | .. raw:: html | |
204 | ||
205 | ---> | |
206 | ||
207 | .. toctree:: | |
208 | :maxdepth: 1 | |
209 | :hidden: | |
210 | ||
211 | Experimental Features <experimental-features> |