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1 | |
2 | CephFS Administrative commands | |
3 | ============================== | |
4 | ||
5 | Filesystems | |
6 | ----------- | |
7 | ||
8 | These commands operate on the CephFS filesystems in your Ceph cluster. | |
9 | Note that by default only one filesystem is permitted: to enable | |
10 | creation of multiple filesystems use ``ceph fs flag set enable_multiple true``. | |
11 | ||
12 | :: | |
13 | ||
14 | fs new <filesystem name> <metadata pool name> <data pool name> | |
15 | ||
16 | :: | |
17 | ||
18 | fs ls | |
19 | ||
20 | :: | |
21 | ||
22 | fs rm <filesystem name> [--yes-i-really-mean-it] | |
23 | ||
24 | :: | |
25 | ||
26 | fs reset <filesystem name> | |
27 | ||
28 | :: | |
29 | ||
30 | fs get <filesystem name> | |
31 | ||
32 | :: | |
33 | ||
34 | fs set <filesystem name> <var> <val> | |
35 | ||
36 | :: | |
37 | ||
38 | fs add_data_pool <filesystem name> <pool name/id> | |
39 | ||
40 | :: | |
41 | ||
42 | fs rm_data_pool <filesystem name> <pool name/id> | |
43 | ||
44 | ||
31f18b77 FG |
45 | Settings |
46 | -------- | |
47 | ||
48 | :: | |
49 | ||
50 | fs set <fs name> max_file_size <size in bytes> | |
51 | ||
52 | CephFS has a configurable maximum file size, and it's 1TB by default. | |
53 | You may wish to set this limit higher if you expect to store large files | |
54 | in CephFS. It is a 64-bit field. | |
55 | ||
56 | Setting ``max_file_size`` to 0 does not disable the limit. It would | |
57 | simply limit clients to only creating empty files. | |
58 | ||
59 | ||
60 | Maximum file sizes and performance | |
61 | ---------------------------------- | |
62 | ||
63 | CephFS enforces the maximum file size limit at the point of appending to | |
64 | files or setting their size. It does not affect how anything is stored. | |
65 | ||
66 | When users create a file of an enormous size (without necessarily | |
67 | writing any data to it), some operations (such as deletes) cause the MDS | |
68 | to have to do a large number of operations to check if any of the RADOS | |
69 | objects within the range that could exist (according to the file size) | |
70 | really existed. | |
71 | ||
72 | The ``max_file_size`` setting prevents users from creating files that | |
73 | appear to be eg. exabytes in size, causing load on the MDS as it tries | |
74 | to enumerate the objects during operations like stats or deletes. | |
75 | ||
76 | ||
28e407b8 AA |
77 | Taking the cluster down |
78 | ----------------------- | |
79 | ||
80 | Taking a CephFS cluster down is done by reducing the number of ranks to 1, | |
81 | setting the cluster_down flag, and then failing the last rank. For example: | |
82 | ||
83 | :: | |
84 | ceph fs set <fs_name> max_mds 1 | |
85 | ceph mds deactivate <fs_name>:1 # rank 2 of 2 | |
86 | ceph status # wait for rank 1 to finish stopping | |
87 | ceph fs set <fs_name> cluster_down true | |
88 | ceph mds fail <fs_name>:0 | |
89 | ||
90 | Setting the ``cluster_down`` flag prevents standbys from taking over the failed | |
91 | rank. | |
92 | ||
7c673cae FG |
93 | Daemons |
94 | ------- | |
95 | ||
96 | These commands act on specific mds daemons or ranks. | |
97 | ||
98 | :: | |
99 | ||
224ce89b | 100 | mds fail <gid/name/role> |
7c673cae | 101 | |
224ce89b WB |
102 | Mark an MDS daemon as failed. This is equivalent to what the cluster |
103 | would do if an MDS daemon had failed to send a message to the mon | |
104 | for ``mds_beacon_grace`` second. If the daemon was active and a suitable | |
105 | standby is available, using ``mds fail`` will force a failover to the standby. | |
106 | ||
107 | If the MDS daemon was in reality still running, then using ``mds fail`` | |
108 | will cause the daemon to restart. If it was active and a standby was | |
109 | available, then the "failed" daemon will return as a standby. | |
7c673cae FG |
110 | |
111 | :: | |
112 | ||
113 | mds deactivate <role> | |
114 | ||
224ce89b WB |
115 | Deactivate an MDS, causing it to flush its entire journal to |
116 | backing RADOS objects and close all open client sessions. Deactivating an MDS | |
117 | is primarily intended for bringing down a rank after reducing the number of | |
c07f9fc5 FG |
118 | active MDS (max_mds). Once the rank is deactivated, the MDS daemon will rejoin the |
119 | cluster as a standby. | |
120 | ``<role>`` can take one of three forms: | |
121 | ||
122 | :: | |
123 | ||
124 | <fs_name>:<rank> | |
125 | <fs_id>:<rank> | |
126 | <rank> | |
224ce89b WB |
127 | |
128 | Use ``mds deactivate`` in conjunction with adjustments to ``max_mds`` to | |
129 | shrink an MDS cluster. See :doc:`/cephfs/multimds` | |
130 | ||
7c673cae FG |
131 | :: |
132 | ||
133 | tell mds.<daemon name> | |
134 | ||
135 | :: | |
136 | ||
137 | mds metadata <gid/name/role> | |
138 | ||
139 | :: | |
140 | ||
141 | mds repaired <role> | |
142 | ||
143 | ||
144 | Global settings | |
145 | --------------- | |
146 | ||
147 | :: | |
148 | ||
149 | fs dump | |
150 | ||
151 | :: | |
152 | ||
153 | fs flag set <flag name> <flag val> [<confirmation string>] | |
154 | ||
155 | "flag name" must be one of ['enable_multiple'] | |
156 | ||
157 | Some flags require you to confirm your intentions with "--yes-i-really-mean-it" | |
158 | or a similar string they will prompt you with. Consider these actions carefully | |
159 | before proceeding; they are placed on especially dangerous activities. | |
160 | ||
161 | ||
162 | Advanced | |
163 | -------- | |
164 | ||
165 | These commands are not required in normal operation, and exist | |
166 | for use in exceptional circumstances. Incorrect use of these | |
167 | commands may cause serious problems, such as an inaccessible | |
168 | filesystem. | |
169 | ||
170 | :: | |
171 | ||
172 | mds compat rm_compat | |
173 | ||
174 | :: | |
175 | ||
176 | mds compat rm_incompat | |
177 | ||
178 | :: | |
179 | ||
180 | mds compat show | |
181 | ||
182 | :: | |
183 | ||
184 | mds getmap | |
185 | ||
186 | :: | |
187 | ||
188 | mds set_state | |
189 | ||
190 | :: | |
191 | ||
192 | mds rmfailed | |
193 | ||
194 | Legacy | |
195 | ------ | |
196 | ||
31f18b77 FG |
197 | The ``ceph mds set`` command is the deprecated version of ``ceph fs set``, |
198 | from before there was more than one filesystem per cluster. It operates | |
199 | on whichever filesystem is marked as the default (see ``ceph fs | |
200 | set-default``.) | |
201 | ||
7c673cae FG |
202 | :: |
203 | ||
204 | mds stat | |
205 | mds dump # replaced by "fs get" | |
206 | mds stop # replaced by "mds deactivate" | |
207 | mds set_max_mds # replaced by "fs set max_mds" | |
208 | mds set # replaced by "fs set" | |
209 | mds cluster_down # replaced by "fs set cluster_down" | |
210 | mds cluster_up # replaced by "fs set cluster_up" | |
211 | mds newfs # replaced by "fs new" | |
212 | mds add_data_pool # replaced by "fs add_data_pool" | |
213 | mds remove_data_pool #replaced by "fs remove_data_pool" | |
214 |