X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fceph%2Fdoc%2Fcephfs%2Fadministration.rst;fp=src%2Fceph%2Fdoc%2Fcephfs%2Fadministration.rst;h=e9d9195557d19cae0865985f2d09304855676c07;hb=812ff6ca9fcd3e629e49d4328905f33eee8ca3f5;hp=0000000000000000000000000000000000000000;hpb=15280273faafb77777eab341909a3f495cf248d9;p=stor4nfv.git diff --git a/src/ceph/doc/cephfs/administration.rst b/src/ceph/doc/cephfs/administration.rst new file mode 100644 index 0000000..e9d9195 --- /dev/null +++ b/src/ceph/doc/cephfs/administration.rst @@ -0,0 +1,198 @@ + +CephFS Administrative commands +============================== + +Filesystems +----------- + +These commands operate on the CephFS filesystems in your Ceph cluster. +Note that by default only one filesystem is permitted: to enable +creation of multiple filesystems use ``ceph fs flag set enable_multiple true``. + +:: + + fs new + +:: + + fs ls + +:: + + fs rm [--yes-i-really-mean-it] + +:: + + fs reset + +:: + + fs get + +:: + + fs set + +:: + + fs add_data_pool + +:: + + fs rm_data_pool + + +Settings +-------- + +:: + + fs set max_file_size + +CephFS has a configurable maximum file size, and it's 1TB by default. +You may wish to set this limit higher if you expect to store large files +in CephFS. It is a 64-bit field. + +Setting ``max_file_size`` to 0 does not disable the limit. It would +simply limit clients to only creating empty files. + + +Maximum file sizes and performance +---------------------------------- + +CephFS enforces the maximum file size limit at the point of appending to +files or setting their size. It does not affect how anything is stored. + +When users create a file of an enormous size (without necessarily +writing any data to it), some operations (such as deletes) cause the MDS +to have to do a large number of operations to check if any of the RADOS +objects within the range that could exist (according to the file size) +really existed. + +The ``max_file_size`` setting prevents users from creating files that +appear to be eg. exabytes in size, causing load on the MDS as it tries +to enumerate the objects during operations like stats or deletes. + + +Daemons +------- + +These commands act on specific mds daemons or ranks. + +:: + + mds fail + +Mark an MDS daemon as failed. This is equivalent to what the cluster +would do if an MDS daemon had failed to send a message to the mon +for ``mds_beacon_grace`` second. If the daemon was active and a suitable +standby is available, using ``mds fail`` will force a failover to the standby. + +If the MDS daemon was in reality still running, then using ``mds fail`` +will cause the daemon to restart. If it was active and a standby was +available, then the "failed" daemon will return as a standby. + +:: + + mds deactivate + +Deactivate an MDS, causing it to flush its entire journal to +backing RADOS objects and close all open client sessions. Deactivating an MDS +is primarily intended for bringing down a rank after reducing the number of +active MDS (max_mds). Once the rank is deactivated, the MDS daemon will rejoin the +cluster as a standby. +```` can take one of three forms: + +:: + + : + : + + +Use ``mds deactivate`` in conjunction with adjustments to ``max_mds`` to +shrink an MDS cluster. See :doc:`/cephfs/multimds` + +:: + + tell mds. + +:: + + mds metadata + +:: + + mds repaired + + +Global settings +--------------- + +:: + + fs dump + +:: + + fs flag set [] + +"flag name" must be one of ['enable_multiple'] + +Some flags require you to confirm your intentions with "--yes-i-really-mean-it" +or a similar string they will prompt you with. Consider these actions carefully +before proceeding; they are placed on especially dangerous activities. + + +Advanced +-------- + +These commands are not required in normal operation, and exist +for use in exceptional circumstances. Incorrect use of these +commands may cause serious problems, such as an inaccessible +filesystem. + +:: + + mds compat rm_compat + +:: + + mds compat rm_incompat + +:: + + mds compat show + +:: + + mds getmap + +:: + + mds set_state + +:: + + mds rmfailed + +Legacy +------ + +The ``ceph mds set`` command is the deprecated version of ``ceph fs set``, +from before there was more than one filesystem per cluster. It operates +on whichever filesystem is marked as the default (see ``ceph fs +set-default``.) + +:: + + mds stat + mds dump # replaced by "fs get" + mds stop # replaced by "mds deactivate" + mds set_max_mds # replaced by "fs set max_mds" + mds set # replaced by "fs set" + mds cluster_down # replaced by "fs set cluster_down" + mds cluster_up # replaced by "fs set cluster_up" + mds newfs # replaced by "fs new" + mds add_data_pool # replaced by "fs add_data_pool" + mds remove_data_pool #replaced by "fs remove_data_pool" +