Filestore Config Reference

filestore debug omap check

Description

Debugging check on synchronization. Expensive. For debugging only.

Type

Boolean

Required

No

Default

false

Extended Attributes

Extended Attributes (XATTRs) are an important aspect in your configuration. Some file systems have limits on the number of bytes 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 an key/value database 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.

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.

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.

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.

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.

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.

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.

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.

Type

32-bit Integer

Required

No

Default

2

Synchronization Intervals

Periodically, the filestore needs to 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.

filestore max sync interval

Description

The maximum interval in seconds for synchronizing the filestore.

Type

Double

Required

No

Default

5

filestore min sync interval

Description

The minimum interval in seconds for synchronizing the filestore.

Type

Double

Required

No

Default

.01

Flusher

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.

filestore flusher

Description

Enables the filestore flusher.

Type

Boolean

Required

No

Default

false

Deprecated since version v.65.

filestore flusher max fds

Description

Sets the maximum number of file descriptors for the flusher.

Type

Integer

Required

No

Default

512

Deprecated since version v.65.

filestore sync flush

Description

Enables the synchronization flusher.

Type

Boolean

Required

No

Default

false

Deprecated since version v.65.

filestore fsync flushes journal data

Description

Flush journal data during file system synchronization.

Type

Boolean

Required

No

Default

false

Queue

The following settings provide limits on the size of 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.

Type

Integer

Required

No. Minimal impact on performance.

Default

50

filestore queue max bytes

Description

The maximum number of bytes for an operation.

Type

Integer

Required

No

Default

100 << 20

Timeouts

filestore op threads

Description

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).

Type

Integer

Required

No

Default

60

filestore op thread suicide timeout

Description

The timeout for a commit operation before cancelling the commit (in seconds).

Type

Integer

Required

No

Default

180

B-Tree Filesystem

filestore btrfs snap

Description

Enable snapshots for a btrfs filestore.

Type

Boolean

Required

No. Only used for btrfs.

Default

true

filestore btrfs clone range

Description

Enable cloning ranges for a btrfs filestore.

Type

Boolean

Required

No. Only used for btrfs.

Default

true

Journal

filestore journal parallel

Description

Enables parallel journaling, default for btrfs.

Type

Boolean

Required

No

Default

false

filestore journal writeahead

Description

Enables writeahead journaling, default for xfs.

Type

Boolean

Required

No

Default

false

filestore journal trailing

Description

Deprecated, never use.

Type

Boolean

Required

No

Default

false

Misc

filestore merge threshold

Description

Min number of files in a subdir before merging into parent NOTE: A negative value means to disable subdir merging

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.

Type

Integer

Required

No

Default

2

filestore split rand factor

Description

A random factor added to the split threshold to avoid too many filestore splits occurring at once. See filestore split multiple for details. This can only be changed for an existing osd offline, via ceph-objectstore-tool’s apply-layout-settings command.

Type

Unsigned 32-bit Integer

Required

No

Default

20

filestore update to

Description

Limits filestore auto upgrade to specified version.

Type

Integer

Required

No

Default

1000

filestore blackhole

Description

Drop any new transactions on the floor.

Type

Boolean

Required

No

Default

false

filestore dump file

Description

File onto which store transaction dumps.

Type

Boolean

Required

No

Default

false

filestore kill at

Description

inject a failure at the n’th opportunity

Type

String

Required

No

Default

false

filestore fail eio

Description

Fail/Crash on eio.

Type

Boolean

Required

No

Default

true