Notice

This document is for a development version of Ceph.

Client Configuration

Updating Client Configuration

Certain client configurations can be applied at runtime. To check if a configuration option can be applied (taken into affect by a client) at runtime, use the config help command:

ceph config help debug_client
 debug_client - Debug level for client
 (str, advanced)                                                                                                                      Default: 0/5
 Can update at runtime: true

 The value takes the form 'N' or 'N/M' where N and M are values between 0 and 99.  N is the debug level to log (all values below this are included), and M is the level to gather and buffer in memory.  In the event of a crash, the most recent items <= M are dumped to the log file.

config help tells if a given configuration can be applied at runtime along with the defaults and a description of the configuration option.

To update a configuration option at runtime, use the config set command:

ceph config set client debug_client 20/20

Note that this changes a given configuration for all clients.

To check configured options use the config get command:

ceph config get client
 WHO    MASK LEVEL    OPTION                    VALUE     RO
 client      advanced debug_client              20/20
 global      advanced osd_pool_default_min_size 1
 global      advanced osd_pool_default_size     3

Client Config Reference

client_acl_type

Description

Set the ACL type. Currently, only possible value is "posix_acl" to enable POSIX ACL, or an empty string. This option only takes effect when the fuse_default_permissions is set to false.

Type

String

Default

"" (no ACL enforcement)

client_cache_mid

Description

Set client cache midpoint. The midpoint splits the least recently used lists into a hot and warm list.

Type

Float

Default

0.75

client_cache_size

Description

Set the number of inodes that the client keeps in the metadata cache.

Type

Integer

Default

16384

client_caps_release_delay

Description

Set the delay between capability releases in seconds. The delay sets how many seconds a client waits to release capabilities that it no longer needs in case the capabilities are needed for another user space operation.

Type

Integer

Default

5 (seconds)

client_debug_force_sync_read

Description

If set to true, clients read data directly from OSDs instead of using a local page cache.

Type

Boolean

Default

false

client_dirsize_rbytes

Description

If set to true, use the recursive size of a directory (that is, total of all descendants).

Type

Boolean

Default

true

client_max_inline_size

Description

Set the maximum size of inlined data stored in a file inode rather than in a separate data object in RADOS. This setting only applies if the inline_data flag is set on the MDS map.

Type

Integer

Default

4096

client_metadata

Description

Comma-delimited strings for client metadata sent to each MDS, in addition to the automatically generated version, host name, and other metadata.

Type

String

Default

"" (no additional metadata)

client_mount_gid

Description

Set the group ID of CephFS mount.

Type

Integer

Default

-1

client_mount_timeout

Description

Set the timeout for CephFS mount in seconds.

Type

Float

Default

300.0

client_mount_uid

Description

Set the user ID of CephFS mount.

Type

Integer

Default

-1

client_mountpoint

Description

Directory to mount on the CephFS file system. An alternative to the -r option of the ceph-fuse command.

Type

String

Default

"/"

client_oc

Description

Enable object caching.

Type

Boolean

Default

true

client_oc_max_dirty

Description

Set the maximum number of dirty bytes in the object cache.

Type

Integer

Default

104857600 (100MB)

client_oc_max_dirty_age

Description

Set the maximum age in seconds of dirty data in the object cache before writeback.

Type

Float

Default

5.0 (seconds)

client_oc_max_objects

Description

Set the maximum number of objects in the object cache.

Type

Integer

Default

1000

client_oc_size

Description

Set how many bytes of data will the client cache.

Type

Integer

Default

209715200 (200 MB)

client_oc_target_dirty

Description

Set the target size of dirty data. We recommend to keep this number low.

Type

Integer

Default

8388608 (8MB)

client_permissions

Description

Check client permissions on all I/O operations.

Type

Boolean

Default

true

client_quota

Description

Enable client quota checking if set to true.

Type

Boolean

Default

true

client_quota_df

Description

Report root directory quota for the statfs operation.

Type

Boolean

Default

true

client_readahead_max_bytes

Description

Set the maximum number of bytes that the client reads ahead for future read operations. Overridden by the client_readahead_max_periods setting.

Type

Integer

Default

0 (unlimited)

client_readahead_max_periods

Description

Set the number of file layout periods (object size * number of stripes) that the client reads ahead. Overrides the client_readahead_max_bytes setting.

Type

Integer

Default

4

client_readahead_min

Description

Set the minimum number bytes that the client reads ahead.

Type

Integer

Default

131072 (128KB)

client_reconnect_stale

Description

Automatically reconnect stale session.

Type

Boolean

Default

false

client_snapdir

Description

Set the snapshot directory name.

Type

String

Default

".snap"

client_tick_interval

Description

Set the interval in seconds between capability renewal and other upkeep.

Type

Float

Default

1.0 (seconds)

client_use_random_mds

Description

Choose random MDS for each request.

Type

Boolean

Default

false

fuse_default_permissions

Description

When set to false, ceph-fuse utility checks does its own permissions checking, instead of relying on the permissions enforcement in FUSE. Set to false together with the client acl type=posix_acl option to enable POSIX ACL.

Type

Boolean

Default

true

fuse_max_write

Description

Set the maximum number of bytes in a single write operation. A value of 0 indicates no change; the FUSE default of 128 kbytes remains in force.

Type

Integer

Default

0

fuse_disable_pagecache

Description

If set to true, kernel page cache is disabled for ceph-fuse mounts. When multiple clients read/write to a file at the same time, readers may get stale data from page cache. Due to limitations of FUSE, ceph-fuse can’t disable page cache dynamically.

Type

Boolean

Default

false

Developer Options

Important

These options are internal. They are listed here only to complete the list of options.

client_debug_getattr_caps

Description

Check if the reply from the MDS contains required capabilities.

Type

Boolean

Default

false

client_debug_inject_tick_delay

Description

Add artificial delay between client ticks.

Type

Integer

Default

0

client_inject_fixed_oldest_tid

Description

Type

Boolean

Default

false

client_inject_release_failure

Description

Type

Boolean

Default

false

client_trace

Description

The path to the trace file for all file operations. The output is designed to be used by the Ceph synthetic client.

Type

String

Default

"" (disabled)