Filestore Config Reference
============================
-The Filestore back end is no longer the default when creating new OSDs,
-though Filestore OSDs are still supported.
+.. note:: Since the Luminous release of Ceph, Filestore has not been Ceph's
+ default storage back end. Since the Luminous release of Ceph, BlueStore has
+ been Ceph's default storage back end. However, Filestore OSDs are still
+ supported. See :ref:`OSD Back Ends
+ <rados_config_storage_devices_osd_backends>`. See :ref:`BlueStore Migration
+ <rados_operations_bluestore_migration>` for instructions explaining how to
+ replace an existing Filestore back end with a BlueStore back end.
-``filestore debug omap check``
+
+``filestore_debug_omap_check``
:Description: Debugging check on synchronization. Expensive. For debugging only.
:Type: Boolean
Extended Attributes
===================
-Extended Attributes (XATTRs) are important for Filestore OSDs.
-Some file systems have limits on the number of bytes that can be stored in XATTRs.
-Additionally, in some cases, the file system may not be as fast as an alternative
-method of storing XATTRs. The following settings may help improve performance
-by using a method of storing XATTRs that is extrinsic to the underlying file system.
-
-Ceph XATTRs are stored as ``inline xattr``, using the XATTRs provided
-by the underlying file system, if it does not impose a size limit. If
-there is a size limit (4KB total on ext4, for instance), some Ceph
-XATTRs will be stored in a key/value database when either the
+Extended Attributes (XATTRs) are important for Filestore OSDs. However, Certain
+disadvantages can occur when the underlying file system is used for the storage
+of XATTRs: some file systems have limits on the number of bytes that can be
+stored in XATTRs, and your file system might in some cases therefore run slower
+than would an alternative method of storing XATTRs. For this reason, a method
+of storing XATTRs extrinsic to the underlying file system might improve
+performance. To implement such an extrinsic method, refer to the following
+settings.
+
+If the underlying file system has no size limit, then Ceph XATTRs are stored as
+``inline xattr``, using the XATTRs provided by the file system. But if there is
+a size limit (for example, ext4 imposes a limit of 4 KB total), then some Ceph
+XATTRs will be stored in a key/value database when the limit is reached. More
+precisely, this begins to occur when either the
``filestore_max_inline_xattr_size`` or ``filestore_max_inline_xattrs``
threshold is reached.
``filestore_max_inline_xattr_size``
-:Description: The maximum size of an XATTR stored in the file system (i.e., XFS,
- Btrfs, EXT4, etc.) per object. Should not be larger than the
- file system can handle. Default value of 0 means to use the value
- specific to the underlying file system.
+:Description: Defines the maximum size per object of an XATTR that can be
+ stored in the file system (for example, XFS, Btrfs, ext4). The
+ specified size should not be larger than the file system can
+ handle. Using the default value of 0 instructs Filestore to use
+ the value specific to the file system.
:Type: Unsigned 32-bit Integer
:Required: No
:Default: ``0``
``filestore_max_inline_xattr_size_xfs``
-:Description: The maximum size of an XATTR stored in the XFS file system.
- Only used if ``filestore_max_inline_xattr_size`` == 0.
+:Description: Defines the maximum size of an XATTR that can be stored in the
+ XFS file system. This setting is used only if
+ ``filestore_max_inline_xattr_size`` == 0.
:Type: Unsigned 32-bit Integer
:Required: No
:Default: ``65536``
``filestore_max_inline_xattr_size_btrfs``
-:Description: The maximum size of an XATTR stored in the Btrfs file system.
- Only used if ``filestore_max_inline_xattr_size`` == 0.
+:Description: Defines the maximum size of an XATTR that can be stored in the
+ Btrfs file system. This setting is used only if
+ ``filestore_max_inline_xattr_size`` == 0.
:Type: Unsigned 32-bit Integer
:Required: No
:Default: ``2048``
``filestore_max_inline_xattr_size_other``
-:Description: The maximum size of an XATTR stored in other file systems.
- Only used if ``filestore_max_inline_xattr_size`` == 0.
+:Description: Defines the maximum size of an XATTR that can be stored in other file systems.
+ This setting is used only if ``filestore_max_inline_xattr_size`` == 0.
:Type: Unsigned 32-bit Integer
:Required: No
:Default: ``512``
``filestore_max_inline_xattrs``
-:Description: The maximum number of XATTRs stored in the file system per object.
- Default value of 0 means to use the value specific to the
- underlying file system.
+:Description: Defines the maximum number of XATTRs per object that can be stored in the file system.
+ Using the default value of 0 instructs Filestore to use the value specific to the file system.
:Type: 32-bit Integer
:Required: No
:Default: ``0``
``filestore_max_inline_xattrs_xfs``
-:Description: The maximum number of XATTRs stored in the XFS file system per object.
- Only used if ``filestore_max_inline_xattrs`` == 0.
+:Description: Defines the maximum number of XATTRs per object that can be stored in the XFS file system.
+ This setting is used only if ``filestore_max_inline_xattrs`` == 0.
:Type: 32-bit Integer
:Required: No
:Default: ``10``
``filestore_max_inline_xattrs_btrfs``
-:Description: The maximum number of XATTRs stored in the Btrfs file system per object.
- Only used if ``filestore_max_inline_xattrs`` == 0.
+:Description: Defines the maximum number of XATTRs per object that can be stored in the Btrfs file system.
+ This setting is used only if ``filestore_max_inline_xattrs`` == 0.
:Type: 32-bit Integer
:Required: No
:Default: ``10``
``filestore_max_inline_xattrs_other``
-:Description: The maximum number of XATTRs stored in other file systems per object.
- Only used if ``filestore_max_inline_xattrs`` == 0.
+:Description: Defines the maximum number of XATTRs per object that can be stored in other file systems.
+ This setting is used only if ``filestore_max_inline_xattrs`` == 0.
:Type: 32-bit Integer
:Required: No
:Default: ``2``
Synchronization Intervals
=========================
-Filestore needs to periodically quiesce writes and synchronize the
-file system, which creates a consistent commit point. It can then free journal
-entries up to the commit point. Synchronizing more frequently tends to reduce
-the time required to perform synchronization, and reduces the amount of data
-that needs to remain in the journal. Less frequent synchronization allows the
-backing file system to coalesce small writes and metadata updates more
-optimally, potentially resulting in more efficient synchronization at the
-expense of potentially increasing tail latency.
+Filestore must periodically quiesce writes and synchronize the file system.
+Each synchronization creates a consistent commit point. When the commit point
+is created, Filestore is able to free all journal entries up to that point.
+More-frequent synchronization tends to reduce both synchronization time and
+the amount of data that needs to remain in the journal. Less-frequent
+synchronization allows the backing file system to coalesce small writes and
+metadata updates, potentially increasing synchronization
+efficiency but also potentially increasing tail latency.
+
``filestore_max_sync_interval``
-:Description: The maximum interval in seconds for synchronizing Filestore.
+:Description: Defines the maximum interval (in seconds) for synchronizing Filestore.
:Type: Double
:Required: No
:Default: ``5``
``filestore_min_sync_interval``
-:Description: The minimum interval in seconds for synchronizing Filestore.
+:Description: Defines the minimum interval (in seconds) for synchronizing Filestore.
:Type: Double
:Required: No
:Default: ``.01``
=======
The Filestore flusher forces data from large writes to be written out using
-``sync_file_range`` before the sync in order to (hopefully) reduce the cost of
-the eventual sync. In practice, disabling 'filestore_flusher' seems to improve
-performance in some cases.
+``sync_file_range`` prior to the synchronization.
+Ideally, this action reduces the cost of the eventual synchronization. In practice, however, disabling
+'filestore_flusher' seems in some cases to improve performance.
``filestore_flusher``
-:Description: Enables the filestore flusher.
+:Description: Enables the Filestore flusher.
:Type: Boolean
:Required: No
:Default: ``false``
``filestore_flusher_max_fds``
-:Description: Sets the maximum number of file descriptors for the flusher.
+:Description: Defines the maximum number of file descriptors for the flusher.
:Type: Integer
:Required: No
:Default: ``512``
``filestore_fsync_flushes_journal_data``
-:Description: Flush journal data during file system synchronization.
+:Description: Flushes journal data during file-system synchronization.
:Type: Boolean
:Required: No
:Default: ``false``
Queue
=====
-The following settings provide limits on the size of the Filestore queue.
+The following settings define limits on the size of the Filestore queue:
``filestore_queue_max_ops``
-:Description: Defines the maximum number of in progress operations the file store accepts before blocking on queuing new operations.
+:Description: Defines the maximum number of in-progress operations that Filestore accepts before it blocks the queueing of any new operations.
:Type: Integer
:Required: No. Minimal impact on performance.
:Default: ``50``
``filestore_queue_max_bytes``
-:Description: The maximum number of bytes for an operation.
+:Description: Defines the maximum number of bytes permitted per operation.
:Type: Integer
:Required: No
:Default: ``100 << 20``
-
-
.. index:: filestore; timeouts
Timeouts
========
-
``filestore_op_threads``
-:Description: The number of file system operation threads that execute in parallel.
+:Description: Defines the number of file-system operation threads that execute in parallel.
:Type: Integer
:Required: No
:Default: ``2``
``filestore_op_thread_timeout``
-:Description: The timeout for a file system operation thread (in seconds).
+:Description: Defines the timeout (in seconds) for a file-system operation thread.
:Type: Integer
:Required: No
:Default: ``60``
``filestore_op_thread_suicide_timeout``
-:Description: The timeout for a commit operation before cancelling the commit (in seconds).
+:Description: Defines the timeout (in seconds) for a commit operation before the commit is cancelled.
:Type: Integer
:Required: No
:Default: ``180``
``filestore_btrfs_snap``
-:Description: Enable snapshots for a ``btrfs`` filestore.
+:Description: Enables snapshots for a ``btrfs`` Filestore.
:Type: Boolean
-:Required: No. Only used for ``btrfs``.
+:Required: No. Used only for ``btrfs``.
:Default: ``true``
``filestore_btrfs_clone_range``
-:Description: Enable cloning ranges for a ``btrfs`` filestore.
+:Description: Enables cloning ranges for a ``btrfs`` Filestore.
:Type: Boolean
-:Required: No. Only used for ``btrfs``.
+:Required: No. Used only for ``btrfs``.
:Default: ``true``
``filestore_journal_parallel``
-:Description: Enables parallel journaling, default for Btrfs.
+:Description: Enables parallel journaling, default for ``btrfs``.
:Type: Boolean
:Required: No
:Default: ``false``
``filestore_journal_writeahead``
-:Description: Enables writeahead journaling, default for XFS.
+:Description: Enables write-ahead journaling, default for XFS.
:Type: Boolean
:Required: No
:Default: ``false``
``filestore_journal_trailing``
-:Description: Deprecated, never use.
+:Description: Deprecated. **Never use.**
:Type: Boolean
:Required: No
:Default: ``false``
``filestore_merge_threshold``
-:Description: Min number of files in a subdir before merging into parent
- NOTE: A negative value means to disable subdir merging
+:Description: Defines the minimum number of files permitted in a subdirectory before the subdirectory is merged into its parent directory.
+ NOTE: A negative value means that subdirectory merging is disabled.
:Type: Integer
:Required: No
:Default: ``-10``
``filestore_split_multiple``
:Description: ``(filestore_split_multiple * abs(filestore_merge_threshold) + (rand() % filestore_split_rand_factor)) * 16``
- is the maximum number of files in a subdirectory before
- splitting into child directories.
+ is the maximum number of files permitted in a subdirectory
+ before the subdirectory is split into child directories.
:Type: Integer
:Required: No
``filestore_split_rand_factor``
:Description: A random factor added to the split threshold to avoid
- too many (expensive) Filestore splits occurring at once. See
- ``filestore_split_multiple`` for details.
- This can only be changed offline for an existing OSD,
- via the ``ceph-objectstore-tool apply-layout-settings`` command.
+ too many (expensive) Filestore splits occurring at the same time.
+ For details, see ``filestore_split_multiple``.
+ To change this setting for an existing OSD, it is necessary to take the OSD
+ offline before running the ``ceph-objectstore-tool apply-layout-settings`` command.
:Type: Unsigned 32-bit Integer
:Required: No
``filestore_update_to``
-:Description: Limits Filestore auto upgrade to specified version.
+:Description: Limits automatic upgrades to a specified version of Filestore. Useful in cases in which you want to avoid upgrading to a specific version.
:Type: Integer
:Required: No
:Default: ``1000``
``filestore_blackhole``
-:Description: Drop any new transactions on the floor.
+:Description: Drops any new transactions on the floor, similar to redirecting to NULL.
:Type: Boolean
:Required: No
:Default: ``false``
``filestore_dump_file``
-:Description: File onto which store transaction dumps.
+:Description: Defines the file that transaction dumps are stored on.
:Type: Boolean
:Required: No
:Default: ``false``
``filestore_kill_at``
-:Description: inject a failure at the n'th opportunity
+:Description: Injects a failure at the *n*\th opportunity.
:Type: String
:Required: No
:Default: ``false``
``filestore_fail_eio``
-:Description: Fail/Crash on eio.
+:Description: Fail/Crash on EIO.
:Type: Boolean
:Required: No
:Default: ``true``
-
projects / ceph.git / blobdiff