Appendix D. Ceph File System client configuration reference

This section lists configuration options for Ceph File System (CephFS) FUSE clients. Set them in the Ceph configuration file under the [client] section.

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 the 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 (16 MB)
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
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. Red Hat recommends 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_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 kernel 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 kernel reads ahead. Overrides the client_readahead_max_bytes setting.
Type
Integer
Default
4
client_readahead_min
Description
Set the minimum number bytes that the kernel reads ahead.
Type
Integer
Default
131072 (128KB)
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
client_use_random_mds
Description
Choose random MDS for each request.
Type
Boolean
Default
false
fuse_default_permissions
Description
When set to false, the 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
Developer Options

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. See the ceph-syn(8) manual page for details.
Type
String
Default
"" (disabled)