Filestore Config Reference

    • Description

    • Debugging check on synchronization. Expensive. For debugging only.

    • Type

    • Boolean

    • Required

    • No

    • Default

    • false

    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 alternativemethod of storing XATTRs. The following settings may help improve performanceby using a method of storing XATTRs that is extrinsic to the underlying file system.

    Ceph XATTRs are stored as inline xattr, using the XATTRs providedby the underlying file system, if it does not impose a size limit. Ifthere is a size limit (4KB total on ext4, for instance), some CephXATTRs will be stored in an key/value database when either thefilestore max inline xattr size or filestore max inlinexattrs 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 thefile system can handle. Default value of 0 means to use the valuespecific 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 theunderlying 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 thefile system, which creates a consistent commit point. It can then free journalentries up to the commit point. Synchronizing more frequently tends to reducethe time required to perform synchronization, and reduces the amount of datathat needs to remain in the journal. Less frequent synchronization allows thebacking file system to coalesce small writes and metadata updates moreoptimally–potentially resulting in more efficient synchronization.

    • 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.

    • Double

    • Required

    • No

    • .01

    The filestore flusher forces data from large writes to be written out usingsync file range before the sync in order to (hopefully) reduce the cost ofthe eventual sync. In practice, disabling ‘filestore flusher’ seems to improveperformance 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

    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

    • Description

    • Enable cloning ranges for a btrfs filestore.

    • Type

    • Required

    • Default

    • true

    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 parentNOTE: 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)) 16is the maximum number of files in a subdirectory beforesplitting into child directories.

    • Type

    • Integer

    • Required

    • No

    • Default

    • 2

    filestore split rand factor

    • Description

    • A random factor added to the split threshold to avoidtoo many filestore splits occurring at once. Seefilestore 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

    • Default